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-rw-r--r--.github/workflows/ci.yml17
-rw-r--r--.gitignore2
-rw-r--r--.mailmap1
-rw-r--r--compiler/rustc_codegen_cranelift/src/unsize.rs4
-rw-r--r--compiler/rustc_codegen_ssa/src/base.rs5
-rw-r--r--compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp6
-rw-r--r--compiler/rustc_metadata/src/locator.rs91
-rw-r--r--compiler/rustc_middle/src/query/mod.rs1
-rw-r--r--compiler/rustc_mir_transform/src/coroutine/by_move_body.rs1
-rw-r--r--compiler/rustc_mir_transform/src/coverage/mod.rs5
-rw-r--r--compiler/rustc_next_trait_solver/src/delegate.rs5
-rw-r--r--compiler/rustc_next_trait_solver/src/solve/trait_goals.rs3
-rw-r--r--compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_gnu.rs1
-rw-r--r--compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_musl.rs1
-rw-r--r--compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_ohos.rs4
-rw-r--r--compiler/rustc_trait_selection/src/solve/delegate.rs1
-rw-r--r--compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs2
-rw-r--r--compiler/rustc_trait_selection/src/traits/select/confirmation.rs4
-rw-r--r--library/Cargo.lock16
-rw-r--r--library/alloc/src/collections/linked_list.rs2
-rw-r--r--library/alloc/src/collections/vec_deque/mod.rs2
-rw-r--r--library/alloc/src/lib.rs1
-rw-r--r--library/core/src/iter/sources/repeat_n.rs4
-rw-r--r--library/core/src/lib.rs2
-rw-r--r--library/core/src/macros/mod.rs2
-rw-r--r--library/core/src/ops/index_range.rs11
-rw-r--r--library/core/src/pin.rs20
-rw-r--r--library/core/tests/lazy.rs1
-rw-r--r--library/core/tests/lib.rs2
-rw-r--r--library/core/tests/pin.rs4
-rw-r--r--library/std/Cargo.toml2
-rw-r--r--library/std/src/os/unix/process.rs1
-rw-r--r--library/std/src/os/xous/ffi.rs2
-rw-r--r--library/std/src/random.rs1
-rw-r--r--library/std/src/sys/alloc/xous.rs3
-rw-r--r--library/std/src/sys/pal/xous/args.rs53
-rw-r--r--library/std/src/sys/pal/xous/mod.rs1
-rw-r--r--library/std/src/sys/pal/xous/net/dns.rs1
-rw-r--r--library/std/src/sys/pal/xous/net/mod.rs2
-rw-r--r--library/std/src/sys/pal/xous/os.rs136
-rw-r--r--library/std/src/sys/pal/xous/os/params.rs271
-rw-r--r--library/std/src/sys/pal/xous/os/params/tests.rs75
-rw-r--r--library/std/src/sys/random/arc4random.rs2
-rw-r--r--library/std/src/sys/random/mod.rs1
-rw-r--r--library/std/src/sys/thread_local/native/mod.rs31
-rw-r--r--library/std/src/sys/thread_local/os.rs17
-rw-r--r--library/std/tests/thread.rs23
-rw-r--r--library/unwind/Cargo.toml2
-rwxr-xr-xsrc/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh2
-rw-r--r--src/ci/github-actions/jobs.yml21
-rw-r--r--src/tools/miri/tests/pass/dyn-upcast.rs51
-rw-r--r--src/tools/miri/tests/pass/dyn-upcast.stdout4
-rw-r--r--src/tools/nix-dev-shell/envrc-flake8
-rw-r--r--src/tools/nix-dev-shell/envrc-shell7
-rw-r--r--src/tools/nix-dev-shell/flake.nix33
-rw-r--r--src/tools/nix-dev-shell/shell.nix19
-rw-r--r--src/tools/nix-dev-shell/x/default.nix22
-rw-r--r--src/tools/nix-dev-shell/x/x.rs50
-rw-r--r--tests/codegen/issues/issue-101082.rs5
-rw-r--r--tests/coverage/async_closure.cov-map56
-rw-r--r--tests/coverage/async_closure.coverage24
-rw-r--r--tests/coverage/async_closure.rs15
-rw-r--r--tests/crashes/131190.rs19
-rw-r--r--tests/run-make/avr-rjmp-offset/avr-rjmp-offsets.rs47
-rw-r--r--tests/run-make/avr-rjmp-offset/rmake.rs60
-rw-r--r--tests/ui/command/command-exec.rs8
-rw-r--r--tests/ui/impl-trait/unsized_coercion5.next.stderr14
-rw-r--r--tests/ui/impl-trait/unsized_coercion5.old.stderr18
-rw-r--r--tests/ui/impl-trait/unsized_coercion5.rs2
-rw-r--r--tests/ui/traits/dyn-drop-principal.rs68
-rw-r--r--tests/ui/traits/dyn-drop-principal.run.stdout4
-rw-r--r--tests/ui/traits/dyn-star-drop-principal.rs12
-rw-r--r--tests/ui/traits/dyn-star-drop-principal.stderr11
73 files changed, 1223 insertions, 202 deletions
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 003c1e5d7eb..2fca71716c1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -104,6 +104,18 @@ jobs:
         with:
           fetch-depth: 2
 
+      # Free up disk space on Linux by removing preinstalled components that
+      # we do not need. We do this to enable some of the less resource
+      # intensive jobs to run on free runners, which however also have
+      # less disk space.
+      - name: free up disk space
+        uses: jlumbroso/free-disk-space@54081f138730dfa15788a46383842cd2f914a1be
+        if: contains(matrix.os, 'ubuntu')
+        with:
+          # Removing packages with APT saves ~5 GiB, but takes several
+          # minutes (and potentially removes important packages).
+          large-packages: false
+
       # Rust Log Analyzer can't currently detect the PR number of a GitHub
       # Actions build on its own, so a hint in the log message is needed to
       # point it in the right direction.
@@ -194,6 +206,11 @@ jobs:
       - name: create github artifacts
         run: src/ci/scripts/create-doc-artifacts.sh
 
+      - name: print disk usage
+        run: |
+          echo "disk usage:"
+          df -h
+
       - name: upload artifacts to github
         uses: actions/upload-artifact@v4
         with:
diff --git a/.gitignore b/.gitignore
index b170dca88fa..948133cd76e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -57,6 +57,8 @@ build/
 /src/tools/x/target
 # Created by default with `src/ci/docker/run.sh`
 /obj/
+# Created by nix dev shell / .envrc
+src/tools/nix-dev-shell/flake.lock
 
 ## ICE reports
 rustc-ice-*.txt
diff --git a/.mailmap b/.mailmap
index bdc34c52aa7..56490ca5059 100644
--- a/.mailmap
+++ b/.mailmap
@@ -256,6 +256,7 @@ Jakub Adam Wieczorek <jakub.adam.wieczorek@gmail.com>
 Jakub Adam Wieczorek <jakub.adam.wieczorek@gmail.com> <jakub.bukaj@yahoo.com>
 Jakub Adam Wieczorek <jakub.adam.wieczorek@gmail.com> <jakub@jakub.cc>
 Jakub Adam Wieczorek <jakub.adam.wieczorek@gmail.com> <jakubw@jakubw.net>
+Jakub Beránek <berykubik@gmail.com> <jakub.beranek@vsb.cz>
 James [Undefined] <tpzker@thepuzzlemaker.info>
 James Deng <cnjamesdeng@gmail.com> <cnJamesDeng@gmail.com>
 James Hinshelwood <jameshinshelwood1@gmail.com> <james.hinshelwood@bigpayme.com>
diff --git a/compiler/rustc_codegen_cranelift/src/unsize.rs b/compiler/rustc_codegen_cranelift/src/unsize.rs
index 5c297ebfadb..336934354e1 100644
--- a/compiler/rustc_codegen_cranelift/src/unsize.rs
+++ b/compiler/rustc_codegen_cranelift/src/unsize.rs
@@ -34,7 +34,9 @@ pub(crate) fn unsized_info<'tcx>(
         {
             let old_info =
                 old_info.expect("unsized_info: missing old info for trait upcasting coercion");
-            if data_a.principal_def_id() == data_b.principal_def_id() {
+            let b_principal_def_id = data_b.principal_def_id();
+            if data_a.principal_def_id() == b_principal_def_id || b_principal_def_id.is_none() {
+                // A NOP cast that doesn't actually change anything, should be allowed even with invalid vtables.
                 debug_assert!(
                     validate_trivial_unsize(fx.tcx, data_a, data_b),
                     "NOP unsize vtable changed principal trait ref: {data_a} -> {data_b}"
diff --git a/compiler/rustc_codegen_ssa/src/base.rs b/compiler/rustc_codegen_ssa/src/base.rs
index d91c0f0790d..f3d9a7d37e6 100644
--- a/compiler/rustc_codegen_ssa/src/base.rs
+++ b/compiler/rustc_codegen_ssa/src/base.rs
@@ -147,7 +147,7 @@ pub fn validate_trivial_unsize<'tcx>(
                 infcx.leak_check(universe, None).is_ok()
             })
         }
-        (None, None) => true,
+        (_, None) => true,
         _ => false,
     }
 }
@@ -175,7 +175,8 @@ fn unsized_info<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
         {
             let old_info =
                 old_info.expect("unsized_info: missing old info for trait upcasting coercion");
-            if data_a.principal_def_id() == data_b.principal_def_id() {
+            let b_principal_def_id = data_b.principal_def_id();
+            if data_a.principal_def_id() == b_principal_def_id || b_principal_def_id.is_none() {
                 // Codegen takes advantage of the additional assumption, where if the
                 // principal trait def id of what's being casted doesn't change,
                 // then we don't need to adjust the vtable at all. This
diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index 8f0b1b81276..4b303511dbc 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -490,13 +490,13 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     assert(ArgsCstrBuff[ArgsCstrBuffLen - 1] == '\0');
     auto Arg0 = std::string(ArgsCstrBuff);
     buffer_offset = Arg0.size() + 1;
-    auto ArgsCppStr =
-        std::string(ArgsCstrBuff + buffer_offset, ArgsCstrBuffLen - 1);
+    auto ArgsCppStr = std::string(ArgsCstrBuff + buffer_offset,
+                                  ArgsCstrBuffLen - buffer_offset);
     auto i = 0;
     while (i != std::string::npos) {
       i = ArgsCppStr.find('\0', i + 1);
       if (i != std::string::npos)
-        ArgsCppStr.replace(i, i + 1, " ");
+        ArgsCppStr.replace(i, 1, " ");
     }
     Options.MCOptions.Argv0 = Arg0;
     Options.MCOptions.CommandlineArgs = ArgsCppStr;
diff --git a/compiler/rustc_metadata/src/locator.rs b/compiler/rustc_metadata/src/locator.rs
index 99c673b021a..a4a69ae9514 100644
--- a/compiler/rustc_metadata/src/locator.rs
+++ b/compiler/rustc_metadata/src/locator.rs
@@ -499,8 +499,11 @@ impl<'a> CrateLocator<'a> {
         dylibs: FxIndexMap<PathBuf, PathKind>,
     ) -> Result<Option<(Svh, Library)>, CrateError> {
         let mut slot = None;
-        // Order here matters, rmeta should come first. See comment in
-        // `extract_one` below.
+        // Order here matters, rmeta should come first.
+        //
+        // Make sure there's at most one rlib and at most one dylib.
+        //
+        // See comment in `extract_one` below.
         let source = CrateSource {
             rmeta: self.extract_one(rmetas, CrateFlavor::Rmeta, &mut slot)?,
             rlib: self.extract_one(rlibs, CrateFlavor::Rlib, &mut slot)?,
@@ -706,54 +709,58 @@ impl<'a> CrateLocator<'a> {
         let mut rmetas = FxIndexMap::default();
         let mut dylibs = FxIndexMap::default();
         for loc in &self.exact_paths {
-            if !loc.canonicalized().exists() {
-                return Err(CrateError::ExternLocationNotExist(
-                    self.crate_name,
-                    loc.original().clone(),
-                ));
+            let loc_canon = loc.canonicalized();
+            let loc_orig = loc.original();
+            if !loc_canon.exists() {
+                return Err(CrateError::ExternLocationNotExist(self.crate_name, loc_orig.clone()));
             }
-            if !loc.original().is_file() {
-                return Err(CrateError::ExternLocationNotFile(
-                    self.crate_name,
-                    loc.original().clone(),
-                ));
+            if !loc_orig.is_file() {
+                return Err(CrateError::ExternLocationNotFile(self.crate_name, loc_orig.clone()));
             }
-            let Some(file) = loc.original().file_name().and_then(|s| s.to_str()) else {
-                return Err(CrateError::ExternLocationNotFile(
-                    self.crate_name,
-                    loc.original().clone(),
-                ));
+            // Note to take care and match against the non-canonicalized name:
+            // some systems save build artifacts into content-addressed stores
+            // that do not preserve extensions, and then link to them using
+            // e.g. symbolic links. If we canonicalize too early, we resolve
+            // the symlink, the file type is lost and we might treat rlibs and
+            // rmetas as dylibs.
+            let Some(file) = loc_orig.file_name().and_then(|s| s.to_str()) else {
+                return Err(CrateError::ExternLocationNotFile(self.crate_name, loc_orig.clone()));
             };
-
-            if file.starts_with("lib") && (file.ends_with(".rlib") || file.ends_with(".rmeta"))
-                || file.starts_with(self.target.dll_prefix.as_ref())
-                    && file.ends_with(self.target.dll_suffix.as_ref())
-            {
-                // Make sure there's at most one rlib and at most one dylib.
-                // Note to take care and match against the non-canonicalized name:
-                // some systems save build artifacts into content-addressed stores
-                // that do not preserve extensions, and then link to them using
-                // e.g. symbolic links. If we canonicalize too early, we resolve
-                // the symlink, the file type is lost and we might treat rlibs and
-                // rmetas as dylibs.
-                let loc_canon = loc.canonicalized().clone();
-                let loc = loc.original();
-                if loc.file_name().unwrap().to_str().unwrap().ends_with(".rlib") {
-                    rlibs.insert(loc_canon, PathKind::ExternFlag);
-                } else if loc.file_name().unwrap().to_str().unwrap().ends_with(".rmeta") {
-                    rmetas.insert(loc_canon, PathKind::ExternFlag);
-                } else {
-                    dylibs.insert(loc_canon, PathKind::ExternFlag);
+            // FnMut cannot return reference to captured value, so references
+            // must be taken outside the closure.
+            let rlibs = &mut rlibs;
+            let rmetas = &mut rmetas;
+            let dylibs = &mut dylibs;
+            let type_via_filename = (|| {
+                if file.starts_with("lib") {
+                    if file.ends_with(".rlib") {
+                        return Some(rlibs);
+                    }
+                    if file.ends_with(".rmeta") {
+                        return Some(rmetas);
+                    }
+                }
+                let dll_prefix = self.target.dll_prefix.as_ref();
+                let dll_suffix = self.target.dll_suffix.as_ref();
+                if file.starts_with(dll_prefix) && file.ends_with(dll_suffix) {
+                    return Some(dylibs);
+                }
+                None
+            })();
+            match type_via_filename {
+                Some(type_via_filename) => {
+                    type_via_filename.insert(loc_canon.clone(), PathKind::ExternFlag);
+                }
+                None => {
+                    self.crate_rejections
+                        .via_filename
+                        .push(CrateMismatch { path: loc_orig.clone(), got: String::new() });
                 }
-            } else {
-                self.crate_rejections
-                    .via_filename
-                    .push(CrateMismatch { path: loc.original().clone(), got: String::new() });
             }
         }
 
         // Extract the dylib/rlib/rmeta triple.
-        Ok(self.extract_lib(rlibs, rmetas, dylibs)?.map(|(_, lib)| lib))
+        self.extract_lib(rlibs, rmetas, dylibs).map(|opt| opt.map(|(_, lib)| lib))
     }
 
     pub(crate) fn into_error(self, root: Option<CratePaths>) -> CrateError {
diff --git a/compiler/rustc_middle/src/query/mod.rs b/compiler/rustc_middle/src/query/mod.rs
index 33128bdbf1e..f8ba606e087 100644
--- a/compiler/rustc_middle/src/query/mod.rs
+++ b/compiler/rustc_middle/src/query/mod.rs
@@ -570,6 +570,7 @@ rustc_queries! {
     /// either `#[coverage(on)]` or no coverage attribute was found.
     query coverage_attr_on(key: LocalDefId) -> bool {
         desc { |tcx| "checking for `#[coverage(..)]` on `{}`", tcx.def_path_str(key) }
+        feedable
     }
 
     /// Summarizes coverage IDs inserted by the `InstrumentCoverage` MIR pass
diff --git a/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs b/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs
index cc4b7689d40..2c622b1927e 100644
--- a/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs
+++ b/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs
@@ -223,6 +223,7 @@ pub(crate) fn coroutine_by_move_body_def_id<'tcx>(
 
     // Inherited from the by-ref coroutine.
     body_def.codegen_fn_attrs(tcx.codegen_fn_attrs(coroutine_def_id).clone());
+    body_def.coverage_attr_on(tcx.coverage_attr_on(coroutine_def_id));
     body_def.constness(tcx.constness(coroutine_def_id));
     body_def.coroutine_kind(tcx.coroutine_kind(coroutine_def_id));
     body_def.def_ident_span(tcx.def_ident_span(coroutine_def_id));
diff --git a/compiler/rustc_mir_transform/src/coverage/mod.rs b/compiler/rustc_mir_transform/src/coverage/mod.rs
index d0f30314e79..2e4c503f3ce 100644
--- a/compiler/rustc_mir_transform/src/coverage/mod.rs
+++ b/compiler/rustc_mir_transform/src/coverage/mod.rs
@@ -524,6 +524,11 @@ fn extract_hir_info<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> ExtractedHir
     // FIXME(#79625): Consider improving MIR to provide the information needed, to avoid going back
     // to HIR for it.
 
+    // HACK: For synthetic MIR bodies (async closures), use the def id of the HIR body.
+    if tcx.is_synthetic_mir(def_id) {
+        return extract_hir_info(tcx, tcx.local_parent(def_id));
+    }
+
     let hir_node = tcx.hir_node_by_def_id(def_id);
     let fn_body_id = hir_node.body_id().expect("HIR node is a function with body");
     let hir_body = tcx.hir().body(fn_body_id);
diff --git a/compiler/rustc_next_trait_solver/src/delegate.rs b/compiler/rustc_next_trait_solver/src/delegate.rs
index 76d5f0ea07b..4da1e7fa711 100644
--- a/compiler/rustc_next_trait_solver/src/delegate.rs
+++ b/compiler/rustc_next_trait_solver/src/delegate.rs
@@ -4,9 +4,8 @@ use rustc_type_ir::fold::TypeFoldable;
 use rustc_type_ir::solve::{Certainty, Goal, NoSolution, SolverMode};
 use rustc_type_ir::{self as ty, InferCtxtLike, Interner};
 
-pub trait SolverDelegate:
-    Deref<Target: InferCtxtLike<Interner = <Self as SolverDelegate>::Interner>> + Sized
-{
+pub trait SolverDelegate: Deref<Target = <Self as SolverDelegate>::Infcx> + Sized {
+    type Infcx: InferCtxtLike<Interner = <Self as SolverDelegate>::Interner>;
     type Interner: Interner;
     fn cx(&self) -> Self::Interner {
         (**self).cx()
diff --git a/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs b/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
index 5828b2ecf34..2cbed0bceb2 100644
--- a/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/trait_goals.rs
@@ -785,7 +785,8 @@ where
         let mut responses = vec![];
         // If the principal def ids match (or are both none), then we're not doing
         // trait upcasting. We're just removing auto traits (or shortening the lifetime).
-        if a_data.principal_def_id() == b_data.principal_def_id() {
+        let b_principal_def_id = b_data.principal_def_id();
+        if a_data.principal_def_id() == b_principal_def_id || b_principal_def_id.is_none() {
             responses.extend(self.consider_builtin_upcast_to_principal(
                 goal,
                 CandidateSource::BuiltinImpl(BuiltinImplSource::Misc),
diff --git a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_gnu.rs b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_gnu.rs
index e869314d4d8..68d51193564 100644
--- a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_gnu.rs
+++ b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_gnu.rs
@@ -23,6 +23,7 @@ pub(crate) fn target() -> Target {
                 | SanitizerSet::LEAK
                 | SanitizerSet::MEMORY
                 | SanitizerSet::THREAD,
+            supports_xray: true,
             direct_access_external_data: Some(false),
             ..base::linux_gnu::opts()
         },
diff --git a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_musl.rs b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_musl.rs
index 398af96127b..25d3559d920 100644
--- a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_musl.rs
+++ b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_musl.rs
@@ -24,6 +24,7 @@ pub(crate) fn target() -> Target {
                 | SanitizerSet::LEAK
                 | SanitizerSet::MEMORY
                 | SanitizerSet::THREAD,
+            supports_xray: true,
             direct_access_external_data: Some(false),
             ..base::linux_musl::opts()
         },
diff --git a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_ohos.rs b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_ohos.rs
index 73d7f0ce4d0..12e026294cf 100644
--- a/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_ohos.rs
+++ b/compiler/rustc_target/src/spec/targets/loongarch64_unknown_linux_ohos.rs
@@ -1,4 +1,4 @@
-use crate::spec::{SanitizerSet, Target, TargetOptions, base};
+use crate::spec::{CodeModel, SanitizerSet, Target, TargetOptions, base};
 
 pub(crate) fn target() -> Target {
     Target {
@@ -13,6 +13,7 @@ pub(crate) fn target() -> Target {
         data_layout: "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128".into(),
         arch: "loongarch64".into(),
         options: TargetOptions {
+            code_model: Some(CodeModel::Medium),
             cpu: "generic".into(),
             features: "+f,+d".into(),
             llvm_abiname: "lp64d".into(),
@@ -22,6 +23,7 @@ pub(crate) fn target() -> Target {
                 | SanitizerSet::LEAK
                 | SanitizerSet::MEMORY
                 | SanitizerSet::THREAD,
+            supports_xray: true,
             direct_access_external_data: Some(false),
             ..base::linux_ohos::opts()
         },
diff --git a/compiler/rustc_trait_selection/src/solve/delegate.rs b/compiler/rustc_trait_selection/src/solve/delegate.rs
index 62f56beb34b..5793ac2fc31 100644
--- a/compiler/rustc_trait_selection/src/solve/delegate.rs
+++ b/compiler/rustc_trait_selection/src/solve/delegate.rs
@@ -36,6 +36,7 @@ impl<'tcx> Deref for SolverDelegate<'tcx> {
 }
 
 impl<'tcx> rustc_next_trait_solver::delegate::SolverDelegate for SolverDelegate<'tcx> {
+    type Infcx = InferCtxt<'tcx>;
     type Interner = TyCtxt<'tcx>;
 
     fn cx(&self) -> TyCtxt<'tcx> {
diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
index 52048ca79f9..aa313a526c1 100644
--- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
@@ -1018,7 +1018,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 // #2 (region bounds).
                 let principal_def_id_a = a_data.principal_def_id();
                 let principal_def_id_b = b_data.principal_def_id();
-                if principal_def_id_a == principal_def_id_b {
+                if principal_def_id_a == principal_def_id_b || principal_def_id_b.is_none() {
                     // We may upcast to auto traits that are either explicitly listed in
                     // the object type's bounds, or implied by the principal trait ref's
                     // supertraits.
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index cc5c7532b50..0ba3b4e6e55 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -1153,6 +1153,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 // We already checked the compatibility of auto traits within `assemble_candidates_for_unsizing`.
                 let iter = data_a
                     .principal()
+                    .filter(|_| {
+                        // optionally drop the principal, if we're unsizing to no principal
+                        data_b.principal().is_some()
+                    })
                     .map(|b| b.map_bound(ty::ExistentialPredicate::Trait))
                     .into_iter()
                     .chain(
diff --git a/library/Cargo.lock b/library/Cargo.lock
index 59b76d8d442..ed9e7dddf52 100644
--- a/library/Cargo.lock
+++ b/library/Cargo.lock
@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "addr2line"
@@ -124,9 +124,9 @@ dependencies = [
 
 [[package]]
 name = "gimli"
-version = "0.30.0"
+version = "0.31.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2e1d97fbe9722ba9bbd0c97051c2956e726562b61f86a25a4360398a40edfc9"
+checksum = "07e28edb80900c19c28f1072f2e8aeca7fa06b23cd4169cefe1af5aa3260783f"
 dependencies = [
  "compiler_builtins",
  "rustc-std-workspace-alloc",
@@ -158,9 +158,9 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.159"
+version = "0.2.161"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "561d97a539a36e26a9a5fad1ea11a3039a67714694aaa379433e580854bc3dc5"
+checksum = "8e9489c2807c139ffd9c1794f4af0ebe86a828db53ecdc7fea2111d0fed085d1"
 dependencies = [
  "rustc-std-workspace-core",
 ]
@@ -406,12 +406,12 @@ dependencies = [
 
 [[package]]
 name = "unwinding"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc55842d0db6329a669d55a623c674b02d677b16bfb2d24857d4089d41eba882"
+checksum = "637d511437df708cee34bdec7ba2f1548d256b7acf3ff20e0a1c559f9bf3a987"
 dependencies = [
  "compiler_builtins",
- "gimli 0.30.0",
+ "gimli 0.31.1",
  "rustc-std-workspace-core",
 ]
 
diff --git a/library/alloc/src/collections/linked_list.rs b/library/alloc/src/collections/linked_list.rs
index 0cd410c0fb7..ca0ea1ec8b2 100644
--- a/library/alloc/src/collections/linked_list.rs
+++ b/library/alloc/src/collections/linked_list.rs
@@ -1082,7 +1082,7 @@ impl<T, A: Allocator> LinkedList<T, A> {
 
     /// Retains only the elements specified by the predicate.
     ///
-    /// In other words, remove all elements `e` for which `f(&e)` returns false.
+    /// In other words, remove all elements `e` for which `f(&mut e)` returns false.
     /// This method operates in place, visiting each element exactly once in the
     /// original order, and preserves the order of the retained elements.
     ///
diff --git a/library/alloc/src/collections/vec_deque/mod.rs b/library/alloc/src/collections/vec_deque/mod.rs
index 54739c50d1d..cf51a84bb6f 100644
--- a/library/alloc/src/collections/vec_deque/mod.rs
+++ b/library/alloc/src/collections/vec_deque/mod.rs
@@ -2122,7 +2122,7 @@ impl<T, A: Allocator> VecDeque<T, A> {
 
     /// Retains only the elements specified by the predicate.
     ///
-    /// In other words, remove all elements `e` for which `f(&e)` returns false.
+    /// In other words, remove all elements `e` for which `f(&mut e)` returns false.
     /// This method operates in place, visiting each element exactly once in the
     /// original order, and preserves the order of the retained elements.
     ///
diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index 0a4a5160d82..ae9b3739858 100644
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -112,7 +112,6 @@
 #![feature(const_eval_select)]
 #![feature(const_heap)]
 #![feature(const_maybe_uninit_write)]
-#![feature(const_pin)]
 #![feature(const_size_of_val)]
 #![feature(const_vec_string_slice)]
 #![feature(core_intrinsics)]
diff --git a/library/core/src/iter/sources/repeat_n.rs b/library/core/src/iter/sources/repeat_n.rs
index 7e162ff387b..cc089c617c0 100644
--- a/library/core/src/iter/sources/repeat_n.rs
+++ b/library/core/src/iter/sources/repeat_n.rs
@@ -8,9 +8,7 @@ use crate::num::NonZero;
 /// The `repeat_n()` function repeats a single value exactly `n` times.
 ///
 /// This is very similar to using [`repeat()`] with [`Iterator::take()`],
-/// but there are two differences:
-/// - `repeat_n()` can return the original value, rather than always cloning.
-/// - `repeat_n()` produces an [`ExactSizeIterator`].
+/// but `repeat_n()` can return the original value, rather than always cloning.
 ///
 /// [`repeat()`]: crate::iter::repeat
 ///
diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 6ed9ccaa694..ad034d3e576 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -129,7 +129,7 @@
 #![feature(const_nonnull_new)]
 #![feature(const_num_midpoint)]
 #![feature(const_option_ext)]
-#![feature(const_pin)]
+#![feature(const_pin_2)]
 #![feature(const_pointer_is_aligned)]
 #![feature(const_ptr_is_null)]
 #![feature(const_ptr_sub_ptr)]
diff --git a/library/core/src/macros/mod.rs b/library/core/src/macros/mod.rs
index 6a4f2af10ef..771c2d31b60 100644
--- a/library/core/src/macros/mod.rs
+++ b/library/core/src/macros/mod.rs
@@ -1550,7 +1550,7 @@ pub(crate) mod builtin {
     /// MODE is any of Forward, Reverse, ForwardFirst, ReverseFirst.
     /// INPUT_ACTIVITIES consists of one valid activity for each input parameter.
     /// OUTPUT_ACTIVITY must not be set if we implicitely return nothing (or explicitely return
-    /// `-> ()`. Otherwise it must be set to one of the allowed activities.
+    /// `-> ()`). Otherwise it must be set to one of the allowed activities.
     #[unstable(feature = "autodiff", issue = "124509")]
     #[allow_internal_unstable(rustc_attrs)]
     #[rustc_builtin_macro]
diff --git a/library/core/src/ops/index_range.rs b/library/core/src/ops/index_range.rs
index 64214eae377..dce3514a159 100644
--- a/library/core/src/ops/index_range.rs
+++ b/library/core/src/ops/index_range.rs
@@ -45,7 +45,8 @@ impl IndexRange {
     #[inline]
     pub const fn len(&self) -> usize {
         // SAFETY: By invariant, this cannot wrap
-        unsafe { self.end.unchecked_sub(self.start) }
+        // Using the intrinsic because a UB check here impedes LLVM optimization. (#131563)
+        unsafe { crate::intrinsics::unchecked_sub(self.end, self.start) }
     }
 
     /// # Safety
@@ -82,7 +83,8 @@ impl IndexRange {
         let mid = if n <= self.len() {
             // SAFETY: We just checked that this will be between start and end,
             // and thus the addition cannot overflow.
-            unsafe { self.start.unchecked_add(n) }
+            // Using the intrinsic avoids a superfluous UB check.
+            unsafe { crate::intrinsics::unchecked_add(self.start, n) }
         } else {
             self.end
         };
@@ -100,8 +102,9 @@ impl IndexRange {
     pub fn take_suffix(&mut self, n: usize) -> Self {
         let mid = if n <= self.len() {
             // SAFETY: We just checked that this will be between start and end,
-            // and thus the addition cannot overflow.
-            unsafe { self.end.unchecked_sub(n) }
+            // and thus the subtraction cannot overflow.
+            // Using the intrinsic avoids a superfluous UB check.
+            unsafe { crate::intrinsics::unchecked_sub(self.end, n) }
         } else {
             self.start
         };
diff --git a/library/core/src/pin.rs b/library/core/src/pin.rs
index fac789dbd99..5d5733d38fc 100644
--- a/library/core/src/pin.rs
+++ b/library/core/src/pin.rs
@@ -1186,7 +1186,7 @@ impl<Ptr: Deref<Target: Unpin>> Pin<Ptr> {
     /// let mut pinned: Pin<&mut u8> = Pin::new(&mut val);
     /// ```
     #[inline(always)]
-    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[rustc_const_stable(feature = "const_pin", since = "CURRENT_RUSTC_VERSION")]
     #[stable(feature = "pin", since = "1.33.0")]
     pub const fn new(pointer: Ptr) -> Pin<Ptr> {
         // SAFETY: the value pointed to is `Unpin`, and so has no requirements
@@ -1214,7 +1214,7 @@ impl<Ptr: Deref<Target: Unpin>> Pin<Ptr> {
     /// assert_eq!(*r, 5);
     /// ```
     #[inline(always)]
-    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[rustc_const_unstable(feature = "const_pin_2", issue = "76654")]
     #[stable(feature = "pin_into_inner", since = "1.39.0")]
     pub const fn into_inner(pin: Pin<Ptr>) -> Ptr {
         pin.__pointer
@@ -1351,7 +1351,7 @@ impl<Ptr: Deref> Pin<Ptr> {
     /// [`pin` module docs]: self
     #[lang = "new_unchecked"]
     #[inline(always)]
-    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[rustc_const_stable(feature = "const_pin", since = "CURRENT_RUSTC_VERSION")]
     #[stable(feature = "pin", since = "1.33.0")]
     pub const unsafe fn new_unchecked(pointer: Ptr) -> Pin<Ptr> {
         Pin { __pointer: pointer }
@@ -1503,7 +1503,7 @@ impl<Ptr: Deref> Pin<Ptr> {
     /// If the underlying data is [`Unpin`], [`Pin::into_inner`] should be used
     /// instead.
     #[inline(always)]
-    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[rustc_const_unstable(feature = "const_pin_2", issue = "76654")]
     #[stable(feature = "pin_into_inner", since = "1.39.0")]
     pub const unsafe fn into_inner_unchecked(pin: Pin<Ptr>) -> Ptr {
         pin.__pointer
@@ -1559,7 +1559,7 @@ impl<'a, T: ?Sized> Pin<&'a T> {
     /// ["pinning projections"]: self#projections-and-structural-pinning
     #[inline(always)]
     #[must_use]
-    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[rustc_const_stable(feature = "const_pin", since = "CURRENT_RUSTC_VERSION")]
     #[stable(feature = "pin", since = "1.33.0")]
     pub const fn get_ref(self) -> &'a T {
         self.__pointer
@@ -1570,7 +1570,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
     /// Converts this `Pin<&mut T>` into a `Pin<&T>` with the same lifetime.
     #[inline(always)]
     #[must_use = "`self` will be dropped if the result is not used"]
-    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[rustc_const_stable(feature = "const_pin", since = "CURRENT_RUSTC_VERSION")]
     #[stable(feature = "pin", since = "1.33.0")]
     pub const fn into_ref(self) -> Pin<&'a T> {
         Pin { __pointer: self.__pointer }
@@ -1588,7 +1588,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
     #[inline(always)]
     #[must_use = "`self` will be dropped if the result is not used"]
     #[stable(feature = "pin", since = "1.33.0")]
-    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[rustc_const_stable(feature = "const_pin", since = "CURRENT_RUSTC_VERSION")]
     pub const fn get_mut(self) -> &'a mut T
     where
         T: Unpin,
@@ -1609,7 +1609,7 @@ impl<'a, T: ?Sized> Pin<&'a mut T> {
     #[inline(always)]
     #[must_use = "`self` will be dropped if the result is not used"]
     #[stable(feature = "pin", since = "1.33.0")]
-    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[rustc_const_stable(feature = "const_pin", since = "CURRENT_RUSTC_VERSION")]
     pub const unsafe fn get_unchecked_mut(self) -> &'a mut T {
         self.__pointer
     }
@@ -1652,7 +1652,7 @@ impl<T: ?Sized> Pin<&'static T> {
     /// This is safe because `T` is borrowed immutably for the `'static` lifetime, which
     /// never ends.
     #[stable(feature = "pin_static_ref", since = "1.61.0")]
-    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[rustc_const_stable(feature = "const_pin", since = "CURRENT_RUSTC_VERSION")]
     pub const fn static_ref(r: &'static T) -> Pin<&'static T> {
         // SAFETY: The 'static borrow guarantees the data will not be
         // moved/invalidated until it gets dropped (which is never).
@@ -1666,7 +1666,7 @@ impl<T: ?Sized> Pin<&'static mut T> {
     /// This is safe because `T` is borrowed for the `'static` lifetime, which
     /// never ends.
     #[stable(feature = "pin_static_ref", since = "1.61.0")]
-    #[rustc_const_unstable(feature = "const_pin", issue = "76654")]
+    #[rustc_const_stable(feature = "const_pin", since = "CURRENT_RUSTC_VERSION")]
     pub const fn static_mut(r: &'static mut T) -> Pin<&'static mut T> {
         // SAFETY: The 'static borrow guarantees the data will not be
         // moved/invalidated until it gets dropped (which is never).
diff --git a/library/core/tests/lazy.rs b/library/core/tests/lazy.rs
index 711511eaf4a..32d0ac51f03 100644
--- a/library/core/tests/lazy.rs
+++ b/library/core/tests/lazy.rs
@@ -114,6 +114,7 @@ fn lazy_type_inference() {
 }
 
 #[test]
+#[cfg(panic = "unwind")]
 #[should_panic = "LazyCell instance has previously been poisoned"]
 fn lazy_force_mut_panic() {
     let mut lazy = LazyCell::<String>::new(|| panic!());
diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs
index bfc0b638b7e..443090097c0 100644
--- a/library/core/tests/lib.rs
+++ b/library/core/tests/lib.rs
@@ -21,7 +21,7 @@
 #![feature(const_likely)]
 #![feature(const_nonnull_new)]
 #![feature(const_option_ext)]
-#![feature(const_pin)]
+#![feature(const_pin_2)]
 #![feature(const_pointer_is_aligned)]
 #![feature(const_three_way_compare)]
 #![feature(const_trait_impl)]
diff --git a/library/core/tests/pin.rs b/library/core/tests/pin.rs
index 7a6af46a743..026d2ca8de2 100644
--- a/library/core/tests/pin.rs
+++ b/library/core/tests/pin.rs
@@ -19,6 +19,10 @@ fn pin_const() {
     const REF: &'static usize = PINNED.get_ref();
     assert_eq!(REF, POINTER);
 
+    const INT: u8 = 42;
+    const STATIC_REF: Pin<&'static u8> = Pin::static_ref(&INT);
+    assert_eq!(*STATIC_REF, INT);
+
     // Note: `pin_mut_const` tests that the methods of `Pin<&mut T>` are usable in a const context.
     // A const fn is used because `&mut` is not (yet) usable in constants.
     const fn pin_mut_const() {
diff --git a/library/std/Cargo.toml b/library/std/Cargo.toml
index 358bd25ff1b..5f8dcde189b 100644
--- a/library/std/Cargo.toml
+++ b/library/std/Cargo.toml
@@ -39,7 +39,7 @@ miniz_oxide = { version = "0.7.0", optional = true, default-features = false }
 addr2line = { version = "0.22.0", optional = true, default-features = false }
 
 [target.'cfg(not(all(windows, target_env = "msvc")))'.dependencies]
-libc = { version = "0.2.159", default-features = false, features = [
+libc = { version = "0.2.161", default-features = false, features = [
     'rustc-dep-of-std',
 ], public = true }
 
diff --git a/library/std/src/os/unix/process.rs b/library/std/src/os/unix/process.rs
index 9aadd949116..ef5adaf2290 100644
--- a/library/std/src/os/unix/process.rs
+++ b/library/std/src/os/unix/process.rs
@@ -154,6 +154,7 @@ pub trait CommandExt: Sealed {
     /// required to gracefully handle errors it is recommended to use the
     /// cross-platform `spawn` instead.
     #[stable(feature = "process_exec2", since = "1.9.0")]
+    #[must_use]
     fn exec(&mut self) -> io::Error;
 
     /// Set executable argument
diff --git a/library/std/src/os/xous/ffi.rs b/library/std/src/os/xous/ffi.rs
index 1a4a940bf35..1db314e9dda 100644
--- a/library/std/src/os/xous/ffi.rs
+++ b/library/std/src/os/xous/ffi.rs
@@ -615,7 +615,7 @@ pub(crate) fn thread_id() -> Result<ThreadId, Error> {
 /// An error is generated if the `knob` is not a valid limit, or if the call
 /// would not succeed.
 pub(crate) fn adjust_limit(knob: Limits, current: usize, new: usize) -> Result<usize, Error> {
-    let mut a0 = Syscall::JoinThread as usize;
+    let mut a0 = Syscall::AdjustProcessLimit as usize;
     let mut a1 = knob as usize;
     let a2 = current;
     let a3 = new;
diff --git a/library/std/src/random.rs b/library/std/src/random.rs
index 604fa4df110..cdb88c795bf 100644
--- a/library/std/src/random.rs
+++ b/library/std/src/random.rs
@@ -40,6 +40,7 @@ use crate::sys::random as sys;
 /// Horizon                | `getrandom` shim
 /// Hurd, L4Re, QNX        | `/dev/urandom`
 /// Redox                  | `/scheme/rand`
+/// RTEMS                  | [`arc4random_buf`](https://docs.rtems.org/branches/master/bsp-howto/getentropy.html)
 /// SGX                    | [`rdrand`](https://en.wikipedia.org/wiki/RDRAND)
 /// SOLID                  | `SOLID_RNG_SampleRandomBytes`
 /// TEEOS                  | `TEE_GenerateRandom`
diff --git a/library/std/src/sys/alloc/xous.rs b/library/std/src/sys/alloc/xous.rs
index 9ea43445d02..321d30e0b11 100644
--- a/library/std/src/sys/alloc/xous.rs
+++ b/library/std/src/sys/alloc/xous.rs
@@ -1,3 +1,6 @@
+// FIXME(static_mut_refs): Do not allow `static_mut_refs` lint
+#![allow(static_mut_refs)]
+
 use crate::alloc::{GlobalAlloc, Layout, System};
 
 #[cfg(not(test))]
diff --git a/library/std/src/sys/pal/xous/args.rs b/library/std/src/sys/pal/xous/args.rs
new file mode 100644
index 00000000000..00c44ca220a
--- /dev/null
+++ b/library/std/src/sys/pal/xous/args.rs
@@ -0,0 +1,53 @@
+use crate::ffi::OsString;
+use crate::sys::pal::xous::os::get_application_parameters;
+use crate::sys::pal::xous::os::params::ArgumentList;
+use crate::{fmt, vec};
+
+pub struct Args {
+    parsed_args_list: vec::IntoIter<OsString>,
+}
+
+pub fn args() -> Args {
+    let Some(params) = get_application_parameters() else {
+        return Args { parsed_args_list: vec![].into_iter() };
+    };
+
+    for param in params {
+        if let Ok(args) = ArgumentList::try_from(&param) {
+            let mut parsed_args = vec![];
+            for arg in args {
+                parsed_args.push(arg.into());
+            }
+            return Args { parsed_args_list: parsed_args.into_iter() };
+        }
+    }
+    Args { parsed_args_list: vec![].into_iter() }
+}
+
+impl fmt::Debug for Args {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.parsed_args_list.as_slice().fmt(f)
+    }
+}
+
+impl Iterator for Args {
+    type Item = OsString;
+    fn next(&mut self) -> Option<OsString> {
+        self.parsed_args_list.next()
+    }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.parsed_args_list.size_hint()
+    }
+}
+
+impl DoubleEndedIterator for Args {
+    fn next_back(&mut self) -> Option<OsString> {
+        self.parsed_args_list.next_back()
+    }
+}
+
+impl ExactSizeIterator for Args {
+    fn len(&self) -> usize {
+        self.parsed_args_list.len()
+    }
+}
diff --git a/library/std/src/sys/pal/xous/mod.rs b/library/std/src/sys/pal/xous/mod.rs
index b211e94db65..a64cd068560 100644
--- a/library/std/src/sys/pal/xous/mod.rs
+++ b/library/std/src/sys/pal/xous/mod.rs
@@ -1,6 +1,5 @@
 #![forbid(unsafe_op_in_unsafe_fn)]
 
-#[path = "../unsupported/args.rs"]
 pub mod args;
 #[path = "../unsupported/env.rs"]
 pub mod env;
diff --git a/library/std/src/sys/pal/xous/net/dns.rs b/library/std/src/sys/pal/xous/net/dns.rs
index d0083c61837..1a2b56b4da5 100644
--- a/library/std/src/sys/pal/xous/net/dns.rs
+++ b/library/std/src/sys/pal/xous/net/dns.rs
@@ -6,6 +6,7 @@ use crate::os::xous::ffi::lend_mut;
 use crate::os::xous::services::{DnsLendMut, dns_server};
 
 pub struct DnsError {
+    #[allow(dead_code)]
     pub code: u8,
 }
 
diff --git a/library/std/src/sys/pal/xous/net/mod.rs b/library/std/src/sys/pal/xous/net/mod.rs
index dd8b765aa74..3e18ed24208 100644
--- a/library/std/src/sys/pal/xous/net/mod.rs
+++ b/library/std/src/sys/pal/xous/net/mod.rs
@@ -60,6 +60,7 @@ pub mod netc {
 
     #[derive(Copy, Clone)]
     pub struct sockaddr_in {
+        #[allow(dead_code)]
         pub sin_family: sa_family_t,
         pub sin_port: u16,
         pub sin_addr: in_addr,
@@ -72,6 +73,7 @@ pub mod netc {
 
     #[derive(Copy, Clone)]
     pub struct sockaddr_in6 {
+        #[allow(dead_code)]
         pub sin6_family: sa_family_t,
         pub sin6_port: u16,
         pub sin6_addr: in6_addr,
diff --git a/library/std/src/sys/pal/xous/os.rs b/library/std/src/sys/pal/xous/os.rs
index 8f8f35428c4..b0ab01a6383 100644
--- a/library/std/src/sys/pal/xous/os.rs
+++ b/library/std/src/sys/pal/xous/os.rs
@@ -1,29 +1,35 @@
 use super::unsupported;
+use crate::collections::HashMap;
 use crate::error::Error as StdError;
 use crate::ffi::{OsStr, OsString};
 use crate::marker::PhantomData;
 use crate::os::xous::ffi::Error as XousError;
 use crate::path::{self, PathBuf};
-use crate::{fmt, io};
+use crate::sync::atomic::{AtomicPtr, AtomicUsize, Ordering};
+use crate::sync::{Mutex, Once};
+use crate::{fmt, io, vec};
+
+pub(crate) mod params;
+
+static PARAMS_ADDRESS: AtomicPtr<u8> = AtomicPtr::new(core::ptr::null_mut());
 
 #[cfg(not(test))]
 #[cfg(feature = "panic_unwind")]
 mod eh_unwinding {
-    pub(crate) struct EhFrameFinder(usize /* eh_frame */);
-    pub(crate) static mut EH_FRAME_SETTINGS: EhFrameFinder = EhFrameFinder(0);
-    impl EhFrameFinder {
-        pub(crate) unsafe fn init(&mut self, eh_frame: usize) {
-            unsafe {
-                EH_FRAME_SETTINGS.0 = eh_frame;
-            }
-        }
-    }
+    pub(crate) struct EhFrameFinder;
+    pub(crate) static mut EH_FRAME_ADDRESS: usize = 0;
+    pub(crate) static EH_FRAME_SETTINGS: EhFrameFinder = EhFrameFinder;
+
     unsafe impl unwind::EhFrameFinder for EhFrameFinder {
         fn find(&self, _pc: usize) -> Option<unwind::FrameInfo> {
-            Some(unwind::FrameInfo {
-                text_base: None,
-                kind: unwind::FrameInfoKind::EhFrame(self.0),
-            })
+            if unsafe { EH_FRAME_ADDRESS == 0 } {
+                None
+            } else {
+                Some(unwind::FrameInfo {
+                    text_base: None,
+                    kind: unwind::FrameInfoKind::EhFrame(unsafe { EH_FRAME_ADDRESS }),
+                })
+            }
         }
     }
 }
@@ -41,12 +47,21 @@ mod c_compat {
     }
 
     #[no_mangle]
-    pub extern "C" fn _start(eh_frame: usize) {
+    pub extern "C" fn _start(eh_frame: usize, params_address: usize) {
         #[cfg(feature = "panic_unwind")]
-        unsafe {
-            super::eh_unwinding::EH_FRAME_SETTINGS.init(eh_frame);
+        {
+            unsafe { super::eh_unwinding::EH_FRAME_ADDRESS = eh_frame };
             unwind::set_custom_eh_frame_finder(&super::eh_unwinding::EH_FRAME_SETTINGS).ok();
         }
+
+        if params_address != 0 {
+            let params_address = crate::ptr::with_exposed_provenance_mut::<u8>(params_address);
+            if unsafe {
+                super::params::ApplicationParameters::new_from_ptr(params_address).is_some()
+            } {
+                super::PARAMS_ADDRESS.store(params_address, core::sync::atomic::Ordering::Relaxed);
+            }
+        }
         exit(unsafe { main() });
     }
 
@@ -116,44 +131,103 @@ pub fn current_exe() -> io::Result<PathBuf> {
     unsupported()
 }
 
-pub struct Env(!);
+pub(crate) fn get_application_parameters() -> Option<params::ApplicationParameters> {
+    let params_address = PARAMS_ADDRESS.load(Ordering::Relaxed);
+    unsafe { params::ApplicationParameters::new_from_ptr(params_address) }
+}
+
+// ---------- Environment handling ---------- //
+static ENV: AtomicUsize = AtomicUsize::new(0);
+static ENV_INIT: Once = Once::new();
+type EnvStore = Mutex<HashMap<OsString, OsString>>;
+
+fn get_env_store() -> &'static EnvStore {
+    ENV_INIT.call_once(|| {
+        let env_store = EnvStore::default();
+        if let Some(params) = get_application_parameters() {
+            for param in params {
+                if let Ok(envs) = params::EnvironmentBlock::try_from(&param) {
+                    let mut env_store = env_store.lock().unwrap();
+                    for env in envs {
+                        env_store.insert(env.key.into(), env.value.into());
+                    }
+                    break;
+                }
+            }
+        }
+        ENV.store(Box::into_raw(Box::new(env_store)) as _, Ordering::Relaxed)
+    });
+    unsafe { &*core::ptr::with_exposed_provenance::<EnvStore>(ENV.load(Ordering::Relaxed)) }
+}
+
+pub struct Env {
+    iter: vec::IntoIter<(OsString, OsString)>,
+}
+
+// FIXME(https://github.com/rust-lang/rust/issues/114583): Remove this when <OsStr as Debug>::fmt matches <str as Debug>::fmt.
+pub struct EnvStrDebug<'a> {
+    slice: &'a [(OsString, OsString)],
+}
+
+impl fmt::Debug for EnvStrDebug<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let Self { slice } = self;
+        f.debug_list()
+            .entries(slice.iter().map(|(a, b)| (a.to_str().unwrap(), b.to_str().unwrap())))
+            .finish()
+    }
+}
 
 impl Env {
     // FIXME(https://github.com/rust-lang/rust/issues/114583): Remove this when <OsStr as Debug>::fmt matches <str as Debug>::fmt.
     pub fn str_debug(&self) -> impl fmt::Debug + '_ {
-        let Self(inner) = self;
-        match *inner {}
+        let Self { iter } = self;
+        EnvStrDebug { slice: iter.as_slice() }
     }
 }
 
 impl fmt::Debug for Env {
-    fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let Self(inner) = self;
-        match *inner {}
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let Self { iter } = self;
+        f.debug_list().entries(iter.as_slice()).finish()
     }
 }
 
+impl !Send for Env {}
+impl !Sync for Env {}
+
 impl Iterator for Env {
     type Item = (OsString, OsString);
     fn next(&mut self) -> Option<(OsString, OsString)> {
-        self.0
+        self.iter.next()
+    }
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        self.iter.size_hint()
     }
 }
 
 pub fn env() -> Env {
-    panic!("not supported on this platform")
+    let clone_to_vec = |map: &HashMap<OsString, OsString>| -> Vec<_> {
+        map.iter().map(|(k, v)| (k.clone(), v.clone())).collect()
+    };
+
+    let iter = clone_to_vec(&*get_env_store().lock().unwrap()).into_iter();
+    Env { iter }
 }
 
-pub fn getenv(_: &OsStr) -> Option<OsString> {
-    None
+pub fn getenv(k: &OsStr) -> Option<OsString> {
+    get_env_store().lock().unwrap().get(k).cloned()
 }
 
-pub unsafe fn setenv(_: &OsStr, _: &OsStr) -> io::Result<()> {
-    Err(io::const_io_error!(io::ErrorKind::Unsupported, "cannot set env vars on this platform"))
+pub unsafe fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {
+    let (k, v) = (k.to_owned(), v.to_owned());
+    get_env_store().lock().unwrap().insert(k, v);
+    Ok(())
 }
 
-pub unsafe fn unsetenv(_: &OsStr) -> io::Result<()> {
-    Err(io::const_io_error!(io::ErrorKind::Unsupported, "cannot unset env vars on this platform"))
+pub unsafe fn unsetenv(k: &OsStr) -> io::Result<()> {
+    get_env_store().lock().unwrap().remove(k);
+    Ok(())
 }
 
 pub fn temp_dir() -> PathBuf {
diff --git a/library/std/src/sys/pal/xous/os/params.rs b/library/std/src/sys/pal/xous/os/params.rs
new file mode 100644
index 00000000000..0d02cf35477
--- /dev/null
+++ b/library/std/src/sys/pal/xous/os/params.rs
@@ -0,0 +1,271 @@
+/// Xous passes a pointer to the parameter block as the second argument.
+/// This is used for passing flags such as environment variables. The
+/// format of the argument block is:
+///
+/// #[repr(C)]
+/// struct BlockHeader {
+///     /// Magic number that identifies this block. Must be printable ASCII.
+///     magic: [u8; 4],
+///
+///     /// The size of the data block. Does not include this header. May be 0.
+///     size: u32,
+///
+///     /// The contents of this block. Varies depending on the block type.
+///     data: [u8; 0],
+/// }
+///
+/// There is a BlockHeader at the start that has magic `AppP`, and the data
+/// that follows is the number of blocks present:
+///
+/// #[repr(C)]
+/// struct ApplicationParameters {
+///     magic: b"AppP",
+///     size: 4u32,
+///
+///     /// The size of the entire application slice, in bytes, including all headers
+///     length: u32,
+///
+///     /// Number of application parameters present. Must be at least 1 (this block)
+///     entries: (parameter_count as u32).to_bytes_le(),
+/// }
+///
+/// #[repr(C)]
+/// struct EnvironmentBlock {
+///     magic: b"EnvB",
+///
+///     /// Total number of bytes, excluding this header
+///     size: 2+data.len(),
+///
+///     /// The number of environment variables
+///     count: u16,
+///
+///     /// Environment variable iteration
+///     data: [u8; 0],
+/// }
+///
+/// Environment variables are present in an `EnvB` block. The `data` section is
+/// a sequence of bytes of the form:
+///
+///      (u16 /* key_len */; [0u8; key_len as usize] /* key */,
+///       u16 /* val_len */ [0u8; val_len as usize])
+///
+/// #[repr(C)]
+/// struct ArgumentList {
+///     magic: b"ArgL",
+///
+///     /// Total number of bytes, excluding this header
+///     size: 2+data.len(),
+///
+///     /// The number of arguments variables
+///     count: u16,
+///
+///     /// Argument variable iteration
+///     data: [u8; 0],
+/// }
+///
+/// Args are just an array of strings that represent command line arguments.
+/// They are a sequence of the form:
+///
+///      (u16 /* val_len */ [0u8; val_len as usize])
+use core::slice;
+
+use crate::ffi::OsString;
+
+/// Magic number indicating we have an environment block
+const ENV_MAGIC: [u8; 4] = *b"EnvB";
+
+/// Command line arguments list
+const ARGS_MAGIC: [u8; 4] = *b"ArgL";
+
+/// Magic number indicating the loader has passed application parameters
+const PARAMS_MAGIC: [u8; 4] = *b"AppP";
+
+#[cfg(test)]
+mod tests;
+
+pub(crate) struct ApplicationParameters {
+    data: &'static [u8],
+    offset: usize,
+    _entries: usize,
+}
+
+impl ApplicationParameters {
+    pub(crate) unsafe fn new_from_ptr(data: *const u8) -> Option<ApplicationParameters> {
+        if data.is_null() {
+            return None;
+        }
+
+        let magic = unsafe { core::slice::from_raw_parts(data, 4) };
+        let block_length = unsafe {
+            u32::from_le_bytes(slice::from_raw_parts(data.add(4), 4).try_into().ok()?) as usize
+        };
+        let data_length = unsafe {
+            u32::from_le_bytes(slice::from_raw_parts(data.add(8), 4).try_into().ok()?) as usize
+        };
+        let entries = unsafe {
+            u32::from_le_bytes(slice::from_raw_parts(data.add(12), 4).try_into().ok()?) as usize
+        };
+
+        // Check for the main header
+        if data_length < 16 || magic != PARAMS_MAGIC || block_length != 8 {
+            return None;
+        }
+
+        let data = unsafe { slice::from_raw_parts(data, data_length) };
+
+        Some(ApplicationParameters { data, offset: 0, _entries: entries })
+    }
+}
+
+impl Iterator for ApplicationParameters {
+    type Item = ApplicationParameter;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        // Fetch magic, ensuring we don't run off the end
+        if self.offset + 4 > self.data.len() {
+            return None;
+        }
+        let magic = &self.data[self.offset..self.offset + 4];
+        self.offset += 4;
+
+        // Fetch header size
+        if self.offset + 4 > self.data.len() {
+            return None;
+        }
+        let size = u32::from_le_bytes(self.data[self.offset..self.offset + 4].try_into().unwrap())
+            as usize;
+        self.offset += 4;
+
+        // Fetch data contents
+        if self.offset + size > self.data.len() {
+            return None;
+        }
+        let data = &self.data[self.offset..self.offset + size];
+        self.offset += size;
+
+        Some(ApplicationParameter { data, magic: magic.try_into().unwrap() })
+    }
+}
+
+pub(crate) struct ApplicationParameter {
+    data: &'static [u8],
+    magic: [u8; 4],
+}
+
+pub(crate) struct ApplicationParameterError;
+
+pub(crate) struct EnvironmentBlock {
+    _count: usize,
+    data: &'static [u8],
+    offset: usize,
+}
+
+impl TryFrom<&ApplicationParameter> for EnvironmentBlock {
+    type Error = ApplicationParameterError;
+
+    fn try_from(value: &ApplicationParameter) -> Result<Self, Self::Error> {
+        if value.data.len() < 2 || value.magic != ENV_MAGIC {
+            return Err(ApplicationParameterError);
+        }
+
+        let count = u16::from_le_bytes(value.data[0..2].try_into().unwrap()) as usize;
+
+        Ok(EnvironmentBlock { data: &value.data[2..], offset: 0, _count: count })
+    }
+}
+
+pub(crate) struct EnvironmentEntry {
+    pub key: &'static str,
+    pub value: &'static str,
+}
+
+impl Iterator for EnvironmentBlock {
+    type Item = EnvironmentEntry;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.offset + 2 > self.data.len() {
+            return None;
+        }
+        let key_len =
+            u16::from_le_bytes(self.data[self.offset..self.offset + 2].try_into().ok()?) as usize;
+        self.offset += 2;
+
+        if self.offset + key_len > self.data.len() {
+            return None;
+        }
+        let key = core::str::from_utf8(&self.data[self.offset..self.offset + key_len]).ok()?;
+        self.offset += key_len;
+
+        if self.offset + 2 > self.data.len() {
+            return None;
+        }
+        let value_len =
+            u16::from_le_bytes(self.data[self.offset..self.offset + 2].try_into().ok()?) as usize;
+        self.offset += 2;
+
+        if self.offset + value_len > self.data.len() {
+            return None;
+        }
+        let value = core::str::from_utf8(&self.data[self.offset..self.offset + value_len]).ok()?;
+        self.offset += value_len;
+
+        Some(EnvironmentEntry { key, value })
+    }
+}
+
+pub(crate) struct ArgumentList {
+    data: &'static [u8],
+    _count: usize,
+    offset: usize,
+}
+
+impl TryFrom<&ApplicationParameter> for ArgumentList {
+    type Error = ApplicationParameterError;
+
+    fn try_from(value: &ApplicationParameter) -> Result<Self, Self::Error> {
+        if value.data.len() < 2 || value.magic != ARGS_MAGIC {
+            return Err(ApplicationParameterError);
+        }
+        let count =
+            u16::from_le_bytes(value.data[0..2].try_into().or(Err(ApplicationParameterError))?)
+                as usize;
+        Ok(ArgumentList { data: &value.data[2..], _count: count, offset: 0 })
+    }
+}
+
+pub(crate) struct ArgumentEntry {
+    value: &'static str,
+}
+
+impl Into<&str> for ArgumentEntry {
+    fn into(self) -> &'static str {
+        self.value
+    }
+}
+
+impl Into<OsString> for ArgumentEntry {
+    fn into(self) -> OsString {
+        self.value.into()
+    }
+}
+
+impl Iterator for ArgumentList {
+    type Item = ArgumentEntry;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.offset + 2 > self.data.len() {
+            return None;
+        }
+        let value_len =
+            u16::from_le_bytes(self.data[self.offset..self.offset + 2].try_into().ok()?) as usize;
+        self.offset += 2;
+
+        if self.offset + value_len > self.data.len() {
+            return None;
+        }
+        let value = core::str::from_utf8(&self.data[self.offset..self.offset + value_len]).ok()?;
+        self.offset += value_len;
+
+        Some(ArgumentEntry { value })
+    }
+}
diff --git a/library/std/src/sys/pal/xous/os/params/tests.rs b/library/std/src/sys/pal/xous/os/params/tests.rs
new file mode 100644
index 00000000000..0ef04ee3091
--- /dev/null
+++ b/library/std/src/sys/pal/xous/os/params/tests.rs
@@ -0,0 +1,75 @@
+use super::*;
+use crate::collections::HashMap;
+use crate::io::Write;
+
+fn create_args_test() -> std::io::Result<Vec<u8>> {
+    let mut sample_data = vec![];
+    let mut h = HashMap::new();
+
+    h.insert("foo", "bar");
+    h.insert("baz", "qux");
+    h.insert("some", "val");
+
+    // Magic number
+    sample_data.write_all(&PARAMS_MAGIC)?;
+    // Size of the AppP block
+    sample_data.write_all(&4u32.to_le_bytes())?;
+    // Number of blocks
+    sample_data.write_all(&2u32.to_le_bytes())?;
+
+    // Magic number
+    sample_data.write_all(&ENV_MAGIC)?;
+    let mut data = vec![];
+    for (key, value) in h.iter() {
+        data.extend_from_slice(&(key.len() as u16).to_le_bytes());
+        data.extend_from_slice(key.as_bytes());
+        data.extend_from_slice(&(value.len() as u16).to_le_bytes());
+        data.extend_from_slice(value.as_bytes());
+    }
+    // Size of the EnvB block
+    sample_data.write_all(&(data.len() as u32 + 2).to_le_bytes())?;
+
+    // Number of environment variables
+    sample_data.write_all(&(h.len() as u16).to_le_bytes())?;
+
+    // Environment variables
+    sample_data.write_all(&data)?;
+
+    // Write command line arguments
+    let args = vec!["some", "command", "line variable", "entries"];
+    sample_data.write_all(&ARGS_MAGIC)?;
+    let mut args_size = 0;
+    for entry in args.iter() {
+        args_size += entry.len() + 2;
+    }
+    sample_data.write_all(&(args_size as u32 + 2).to_le_bytes())?;
+    sample_data.write_all(&(args.len() as u16).to_le_bytes())?;
+    for entry in args {
+        sample_data.write_all(&(entry.len() as u16).to_le_bytes())?;
+        sample_data.write_all(entry.as_bytes())?;
+    }
+
+    Ok(sample_data)
+}
+
+#[test]
+fn basic_arg_parsing() {
+    let arg_data = create_args_test().expect("couldn't create test data");
+    for byte in &arg_data {
+        print!("{:02x} ", byte);
+    }
+    println!();
+
+    let args = ApplicationParameters::new(&arg_data).expect("Unable to parse arguments");
+    for arg in args {
+        if let Ok(env) = EnvironmentBlock::try_from(&arg) {
+            for env in env {
+                println!("{}={}", env.key, env.value);
+            }
+        } else if let Ok(args) = ArgumentList::try_from(&arg) {
+            for arg in args {
+                println!("Arg: {}", arg.value);
+            }
+        }
+    }
+}
diff --git a/library/std/src/sys/random/arc4random.rs b/library/std/src/sys/random/arc4random.rs
index 32467e9ebaa..ffabaafbee8 100644
--- a/library/std/src/sys/random/arc4random.rs
+++ b/library/std/src/sys/random/arc4random.rs
@@ -12,6 +12,7 @@
 #[cfg(not(any(
     target_os = "haiku",
     target_os = "illumos",
+    target_os = "rtems",
     target_os = "solaris",
     target_os = "vita",
 )))]
@@ -21,6 +22,7 @@ use libc::arc4random_buf;
 #[cfg(any(
     target_os = "haiku", // See https://git.haiku-os.org/haiku/tree/headers/compatibility/bsd/stdlib.h
     target_os = "illumos", // See https://www.illumos.org/man/3C/arc4random
+    target_os = "rtems", // See https://docs.rtems.org/branches/master/bsp-howto/getentropy.html
     target_os = "solaris", // See https://docs.oracle.com/cd/E88353_01/html/E37843/arc4random-3c.html
     target_os = "vita", // See https://github.com/vitasdk/newlib/blob/b89e5bc183b516945f9ee07eef483ecb916e45ff/newlib/libc/include/stdlib.h#L74
 ))]
diff --git a/library/std/src/sys/random/mod.rs b/library/std/src/sys/random/mod.rs
index d625814d15b..edc2cacdfd8 100644
--- a/library/std/src/sys/random/mod.rs
+++ b/library/std/src/sys/random/mod.rs
@@ -17,6 +17,7 @@ cfg_if::cfg_if! {
         target_os = "illumos",
         target_os = "netbsd",
         target_os = "openbsd",
+        target_os = "rtems",
         target_os = "solaris",
         target_os = "vita",
     ))] {
diff --git a/library/std/src/sys/thread_local/native/mod.rs b/library/std/src/sys/thread_local/native/mod.rs
index f498dee0899..a5dffe3c458 100644
--- a/library/std/src/sys/thread_local/native/mod.rs
+++ b/library/std/src/sys/thread_local/native/mod.rs
@@ -49,20 +49,21 @@ pub use lazy::Storage as LazyStorage;
 #[unstable(feature = "thread_local_internals", issue = "none")]
 #[rustc_macro_transparency = "semitransparent"]
 pub macro thread_local_inner {
-    // used to generate the `LocalKey` value for const-initialized thread locals
+    // NOTE: we cannot import `LocalKey`, `LazyStorage` or `EagerStorage` with a `use` because that
+    // can shadow user provided type or type alias with a matching name. Please update the shadowing
+    // test in `tests/thread.rs` if these types are renamed.
+
+    // Used to generate the `LocalKey` value for const-initialized thread locals.
     (@key $t:ty, const $init:expr) => {{
         const __INIT: $t = $init;
 
         unsafe {
-            use $crate::mem::needs_drop;
-            use $crate::thread::LocalKey;
-            use $crate::thread::local_impl::EagerStorage;
-
-            LocalKey::new(const {
-                if needs_drop::<$t>() {
+            $crate::thread::LocalKey::new(const {
+                if $crate::mem::needs_drop::<$t>() {
                     |_| {
                         #[thread_local]
-                        static VAL: EagerStorage<$t> = EagerStorage::new(__INIT);
+                        static VAL: $crate::thread::local_impl::EagerStorage<$t>
+                            = $crate::thread::local_impl::EagerStorage::new(__INIT);
                         VAL.get()
                     }
                 } else {
@@ -84,21 +85,19 @@ pub macro thread_local_inner {
         }
 
         unsafe {
-            use $crate::mem::needs_drop;
-            use $crate::thread::LocalKey;
-            use $crate::thread::local_impl::LazyStorage;
-
-            LocalKey::new(const {
-                if needs_drop::<$t>() {
+            $crate::thread::LocalKey::new(const {
+                if $crate::mem::needs_drop::<$t>() {
                     |init| {
                         #[thread_local]
-                        static VAL: LazyStorage<$t, ()> = LazyStorage::new();
+                        static VAL: $crate::thread::local_impl::LazyStorage<$t, ()>
+                            = $crate::thread::local_impl::LazyStorage::new();
                         VAL.get_or_init(init, __init)
                     }
                 } else {
                     |init| {
                         #[thread_local]
-                        static VAL: LazyStorage<$t, !> = LazyStorage::new();
+                        static VAL: $crate::thread::local_impl::LazyStorage<$t, !>
+                            = $crate::thread::local_impl::LazyStorage::new();
                         VAL.get_or_init(init, __init)
                     }
                 }
diff --git a/library/std/src/sys/thread_local/os.rs b/library/std/src/sys/thread_local/os.rs
index 26ce3322a16..f5a2aaa6c6a 100644
--- a/library/std/src/sys/thread_local/os.rs
+++ b/library/std/src/sys/thread_local/os.rs
@@ -15,19 +15,24 @@ pub macro thread_local_inner {
         $crate::thread::local_impl::thread_local_inner!(@key $t, { const INIT_EXPR: $t = $init; INIT_EXPR })
     },
 
-    // used to generate the `LocalKey` value for `thread_local!`
+    // NOTE: we cannot import `Storage` or `LocalKey` with a `use` because that can shadow user
+    // provided type or type alias with a matching name. Please update the shadowing test in
+    // `tests/thread.rs` if these types are renamed.
+
+    // used to generate the `LocalKey` value for `thread_local!`.
     (@key $t:ty, $init:expr) => {{
         #[inline]
         fn __init() -> $t { $init }
 
+        // NOTE: this cannot import `LocalKey` or `Storage` with a `use` because that can shadow
+        // user provided type or type alias with a matching name. Please update the shadowing test
+        // in `tests/thread.rs` if these types are renamed.
         unsafe {
-            use $crate::thread::LocalKey;
-            use $crate::thread::local_impl::Storage;
-
             // Inlining does not work on windows-gnu due to linking errors around
             // dllimports. See https://github.com/rust-lang/rust/issues/109797.
-            LocalKey::new(#[cfg_attr(windows, inline(never))] |init| {
-                static VAL: Storage<$t> = Storage::new();
+            $crate::thread::LocalKey::new(#[cfg_attr(windows, inline(never))] |init| {
+                static VAL: $crate::thread::local_impl::Storage<$t>
+                    = $crate::thread::local_impl::Storage::new();
                 VAL.get(init, __init)
             })
         }
diff --git a/library/std/tests/thread.rs b/library/std/tests/thread.rs
index 83574176186..1bb17d149fa 100644
--- a/library/std/tests/thread.rs
+++ b/library/std/tests/thread.rs
@@ -39,6 +39,29 @@ fn thread_local_containing_const_statements() {
 }
 
 #[test]
+fn thread_local_hygeiene() {
+    // Previously `thread_local_inner!` had use imports for `LocalKey`, `Storage`, `EagerStorage`
+    // and `LazyStorage`. The use imports will shadow a user-provided type or type alias if the
+    // user-provided type or type alias has the same name. Make sure that this does not happen. See
+    // <https://github.com/rust-lang/rust/issues/131863>.
+    //
+    // NOTE: if the internal implementation details change (i.e. get renamed), this test should be
+    // updated.
+
+    #![allow(dead_code)]
+    type LocalKey = ();
+    type Storage = ();
+    type LazyStorage = ();
+    type EagerStorage = ();
+    thread_local! {
+        static A: LocalKey = const { () };
+        static B: Storage = const { () };
+        static C: LazyStorage = const { () };
+        static D: EagerStorage = const { () };
+    }
+}
+
+#[test]
 // Include an ignore list on purpose, so that new platforms don't miss it
 #[cfg_attr(
     any(
diff --git a/library/unwind/Cargo.toml b/library/unwind/Cargo.toml
index 590de31a678..569a1b3299e 100644
--- a/library/unwind/Cargo.toml
+++ b/library/unwind/Cargo.toml
@@ -22,7 +22,7 @@ cfg-if = "1.0"
 libc = { version = "0.2.140", features = ['rustc-dep-of-std'], default-features = false }
 
 [target.'cfg(target_os = "xous")'.dependencies]
-unwinding = { version = "0.2.1", features = ['rustc-dep-of-std', 'unwinder', 'fde-custom'], default-features = false }
+unwinding = { version = "0.2.3", features = ['rustc-dep-of-std', 'unwinder', 'fde-custom'], default-features = false }
 
 [features]
 
diff --git a/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh b/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh
index 303a2f26c0f..8324d1ec586 100755
--- a/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh
+++ b/src/ci/docker/host-x86_64/x86_64-gnu-tools/checktools.sh
@@ -59,6 +59,8 @@ case $HOST_TARGET in
     # "error: cannot produce cdylib for ... as the target ... does not support these crate types".
     # Only run "pass" tests, which is quite a bit faster.
     #FIXME: Re-enable this once CI issues are fixed
+    # See <https://github.com/rust-lang/rust/issues/127883>
+    # For now, these tests are moved to `x86_64-msvc-ext2` in `src/ci/github-actions/jobs.yml`.
     #python3 "$X_PY" test --stage 2 src/tools/miri --target aarch64-apple-darwin --test-args pass
     #python3 "$X_PY" test --stage 2 src/tools/miri --target i686-pc-windows-gnu --test-args pass
     ;;
diff --git a/src/ci/github-actions/jobs.yml b/src/ci/github-actions/jobs.yml
index 8f49f623afa..d84b904442c 100644
--- a/src/ci/github-actions/jobs.yml
+++ b/src/ci/github-actions/jobs.yml
@@ -5,6 +5,11 @@ runners:
     env: { }
 
   - &job-linux-4c
+    os: ubuntu-20.04
+    <<: *base-job
+
+  # Large runner used mainly for its bigger disk capacity
+  - &job-linux-4c-largedisk
     os: ubuntu-20.04-4core-16gb
     <<: *base-job
 
@@ -127,7 +132,7 @@ auto:
   - image: dist-aarch64-linux
     env:
       CODEGEN_BACKENDS: llvm,cranelift
-    <<: *job-linux-4c
+    <<: *job-linux-4c-largedisk
 
   - image: dist-android
     <<: *job-linux-4c
@@ -148,28 +153,28 @@ auto:
     <<: *job-linux-4c
 
   - image: dist-loongarch64-linux
-    <<: *job-linux-4c
+    <<: *job-linux-4c-largedisk
 
   - image: dist-loongarch64-musl
-    <<: *job-linux-4c
+    <<: *job-linux-4c-largedisk
 
   - image: dist-ohos
     <<: *job-linux-4c
 
   - image: dist-powerpc-linux
-    <<: *job-linux-4c
+    <<: *job-linux-4c-largedisk
 
   - image: dist-powerpc64-linux
-    <<: *job-linux-4c
+    <<: *job-linux-4c-largedisk
 
   - image: dist-powerpc64le-linux
-    <<: *job-linux-4c
+    <<: *job-linux-4c-largedisk
 
   - image: dist-riscv64-linux
     <<: *job-linux-4c
 
   - image: dist-s390x-linux
-    <<: *job-linux-4c
+    <<: *job-linux-4c-largedisk
 
   - image: dist-various-1
     <<: *job-linux-4c
@@ -381,6 +386,8 @@ auto:
     <<: *job-windows-8c
 
   # Temporary builder to workaround CI issues
+  # See <https://github.com/rust-lang/rust/issues/127883>
+  #FIXME: Remove this, and re-enable the same tests in `checktools.sh`, once CI issues are fixed.
   - image: x86_64-msvc-ext2
     env:
       SCRIPT: >
diff --git a/src/tools/miri/tests/pass/dyn-upcast.rs b/src/tools/miri/tests/pass/dyn-upcast.rs
index ff995f38196..306e9ab9c67 100644
--- a/src/tools/miri/tests/pass/dyn-upcast.rs
+++ b/src/tools/miri/tests/pass/dyn-upcast.rs
@@ -9,6 +9,7 @@ fn main() {
     struct_();
     replace_vptr();
     vtable_nop_cast();
+    drop_principal();
 }
 
 fn vtable_nop_cast() {
@@ -430,3 +431,53 @@ fn replace_vptr() {
     let s = S(42);
     invoke_outer(&s);
 }
+
+fn drop_principal() {
+    use std::{alloc::Layout, any::Any};
+
+    const fn yeet_principal(x: Box<dyn Any + Send>) -> Box<dyn Send> {
+        x
+    }
+
+    trait Bar: Send + Sync {}
+
+    impl<T: Send + Sync> Bar for T {}
+
+    const fn yeet_principal_2(x: Box<dyn Bar>) -> Box<dyn Send> {
+        x
+    }
+
+    struct CallMe<F: FnOnce()>(Option<F>);
+
+    impl<F: FnOnce()> CallMe<F> {
+        fn new(f: F) -> Self {
+            CallMe(Some(f))
+        }
+    }
+
+    impl<F: FnOnce()> Drop for CallMe<F> {
+        fn drop(&mut self) {
+            (self.0.take().unwrap())();
+        }
+    }
+
+    fn goodbye() {
+        println!("goodbye");
+    }
+
+    let x = Box::new(CallMe::new(goodbye)) as Box<dyn Any + Send>;
+    let x_layout = Layout::for_value(&*x);
+    let y = yeet_principal(x);
+    let y_layout = Layout::for_value(&*y);
+    assert_eq!(x_layout, y_layout);
+    println!("before");
+    drop(y);
+
+    let x = Box::new(CallMe::new(goodbye)) as Box<dyn Bar>;
+    let x_layout = Layout::for_value(&*x);
+    let y = yeet_principal_2(x);
+    let y_layout = Layout::for_value(&*y);
+    assert_eq!(x_layout, y_layout);
+    println!("before");
+    drop(y);
+}
diff --git a/src/tools/miri/tests/pass/dyn-upcast.stdout b/src/tools/miri/tests/pass/dyn-upcast.stdout
new file mode 100644
index 00000000000..edd99a114a1
--- /dev/null
+++ b/src/tools/miri/tests/pass/dyn-upcast.stdout
@@ -0,0 +1,4 @@
+before
+goodbye
+before
+goodbye
diff --git a/src/tools/nix-dev-shell/envrc-flake b/src/tools/nix-dev-shell/envrc-flake
new file mode 100644
index 00000000000..218d88d8721
--- /dev/null
+++ b/src/tools/nix-dev-shell/envrc-flake
@@ -0,0 +1,8 @@
+# If you want to use this as an .envrc file to create a shell with necessery components 
+# to develop rustc, use the following command in the root of the rusr checkout:
+#	
+# ln -s ./src/tools/nix-dev-shell/envrc-flake ./.envrc && echo .envrc >> .git/info/exclude
+
+if nix flake show path:./src/tools/nix-dev-shell &> /dev/null; then
+  use flake path:./src/tools/nix-dev-shell
+fi
diff --git a/src/tools/nix-dev-shell/envrc-shell b/src/tools/nix-dev-shell/envrc-shell
new file mode 100644
index 00000000000..fb7231a6c30
--- /dev/null
+++ b/src/tools/nix-dev-shell/envrc-shell
@@ -0,0 +1,7 @@
+# If you want to use this as an .envrc file to create a shell with necessery components 
+# to develop rustc, use the following command in the root of the rusr checkout:
+#	
+# ln -s ./src/tools/nix-dev-shell/envrc-shell ./.envrc && echo .envrc >> .git/info/exclude
+
+use nix ./src/tools/nix-dev-shell/shell.nix
+  
diff --git a/src/tools/nix-dev-shell/flake.nix b/src/tools/nix-dev-shell/flake.nix
new file mode 100644
index 00000000000..8ab5e097427
--- /dev/null
+++ b/src/tools/nix-dev-shell/flake.nix
@@ -0,0 +1,33 @@
+{
+  description = "rustc dev shell";
+
+  inputs = {
+    nixpkgs.url      = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url  = "github:numtide/flake-utils";
+  };
+
+  outputs = { self, nixpkgs, flake-utils, ... }:
+	flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = import nixpkgs { inherit system; };
+        x = import ./x { inherit pkgs; };
+      in
+      {
+        devShells.default = with pkgs; mkShell {
+          name = "rustc-dev-shell";
+          nativeBuildInputs = with pkgs; [
+            binutils cmake ninja pkg-config python3 git curl cacert patchelf nix
+          ];
+          buildInputs = with pkgs; [
+            openssl glibc.out glibc.static x
+          ];
+          # Avoid creating text files for ICEs.
+          RUSTC_ICE = "0";
+          # Provide `libstdc++.so.6` for the self-contained lld.
+          LD_LIBRARY_PATH = "${with pkgs; lib.makeLibraryPath [
+            stdenv.cc.cc.lib
+          ]}";
+        };
+      }
+    );
+}
diff --git a/src/tools/nix-dev-shell/shell.nix b/src/tools/nix-dev-shell/shell.nix
new file mode 100644
index 00000000000..8a5cbb7c89e
--- /dev/null
+++ b/src/tools/nix-dev-shell/shell.nix
@@ -0,0 +1,19 @@
+{ pkgs ? import <nixpkgs> {} }:
+let 
+  x = import ./x { inherit pkgs; };
+in
+pkgs.mkShell {
+  name = "rustc";
+  nativeBuildInputs = with pkgs; [
+    binutils cmake ninja pkg-config python3 git curl cacert patchelf nix
+  ];
+  buildInputs = with pkgs; [
+    openssl glibc.out glibc.static x
+  ];
+  # Avoid creating text files for ICEs.
+  RUSTC_ICE = "0";
+  # Provide `libstdc++.so.6` for the self-contained lld.
+  LD_LIBRARY_PATH = "${with pkgs; lib.makeLibraryPath [
+    stdenv.cc.cc.lib
+  ]}";
+}
diff --git a/src/tools/nix-dev-shell/x/default.nix b/src/tools/nix-dev-shell/x/default.nix
new file mode 100644
index 00000000000..e6dfbad6f19
--- /dev/null
+++ b/src/tools/nix-dev-shell/x/default.nix
@@ -0,0 +1,22 @@
+{
+  pkgs ? import <nixpkgs> { },
+}:
+pkgs.stdenv.mkDerivation {
+  name = "x";
+
+  src = ./x.rs;
+  dontUnpack = true;
+
+  nativeBuildInputs = with pkgs; [ rustc ];
+
+  buildPhase = ''
+    PYTHON=${pkgs.lib.getExe pkgs.python3} rustc -Copt-level=3 --crate-name x $src --out-dir $out/bin
+  '';
+
+  meta = with pkgs.lib; {
+    description = "Helper for rust-lang/rust x.py";
+    homepage = "https://github.com/rust-lang/rust/blob/master/src/tools/x";
+    license = licenses.mit;
+    mainProgram = "x";
+  };
+}
diff --git a/src/tools/nix-dev-shell/x/x.rs b/src/tools/nix-dev-shell/x/x.rs
new file mode 100644
index 00000000000..9f83b8fd62e
--- /dev/null
+++ b/src/tools/nix-dev-shell/x/x.rs
@@ -0,0 +1,50 @@
+// git clone https://github.com/rust-lang/rust/blob/0ea7ddcc35a2fcaa5da8a7dcfc118c9fb4a63b95/src/tools/x/src/main.rs
+// patched to stop doing python probing, stop the probe, please dont, i have a python
+//! Run bootstrap from any subdirectory of a rust compiler checkout.
+//!
+//! We prefer `exec`, to avoid adding an extra process in the process tree.
+//! However, since `exec` isn't available on Windows, we indirect through
+//! `exec_or_status`, which will call `exec` on unix and `status` on Windows.
+//!
+//! We use `powershell.exe x.ps1` on Windows, and `sh -c x` on Unix, those are
+//! the ones that call `x.py`. We use `sh -c` on Unix, because it is a standard.
+//! We also don't use `pwsh` on Windows, because it is not installed by default;
+
+use std::env;
+use std::os::unix::process::CommandExt;
+use std::process::{self, Command};
+
+fn main() {
+    match env::args().skip(1).next().as_deref() {
+        Some("--wrapper-version") => {
+            println!("0.1.0");
+            return;
+        }
+        _ => {}
+    }
+    let current = match env::current_dir() {
+        Ok(dir) => dir,
+        Err(err) => {
+            eprintln!("Failed to get current directory: {err}");
+            process::exit(1);
+        }
+    };
+
+    for dir in current.ancestors() {
+        let candidate = dir.join("x.py");
+        if candidate.exists() {
+            let mut cmd = Command::new(env!("PYTHON"));
+            cmd.arg(dir.join("x.py"));
+            cmd.args(env::args().skip(1)).current_dir(dir);
+
+            let error = cmd.exec();
+            eprintln!("Failed to invoke `{:?}`: {}", cmd, error);
+        }
+    }
+
+    eprintln!(
+        "x.py not found. Please run inside of a checkout of `https://github.com/rust-lang/rust`."
+    );
+
+    process::exit(1);
+}
diff --git a/tests/codegen/issues/issue-101082.rs b/tests/codegen/issues/issue-101082.rs
index 550d267a98f..4be1b6cb168 100644
--- a/tests/codegen/issues/issue-101082.rs
+++ b/tests/codegen/issues/issue-101082.rs
@@ -1,4 +1,9 @@
 //@ compile-flags: -O
+//@ revisions: host x86-64-v3
+
+// This particular CPU regressed in #131563
+//@[x86-64-v3] only-x86_64
+//@[x86-64-v3] compile-flags: -Ctarget-cpu=x86-64-v3
 
 #![crate_type = "lib"]
 
diff --git a/tests/coverage/async_closure.cov-map b/tests/coverage/async_closure.cov-map
new file mode 100644
index 00000000000..4d00f0d9b33
--- /dev/null
+++ b/tests/coverage/async_closure.cov-map
@@ -0,0 +1,56 @@
+Function name: async_closure::call_once::<async_closure::main::{closure#0}>
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 07, 01, 00, 2c]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 0
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 7, 1) to (start + 0, 44)
+Highest counter ID seen: c0
+
+Function name: async_closure::call_once::<async_closure::main::{closure#0}>::{closure#0}
+Raw bytes (14): 0x[01, 01, 00, 02, 01, 07, 2c, 01, 0e, 05, 02, 01, 00, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 0
+Number of file 0 mappings: 2
+- Code(Counter(0)) at (prev + 7, 44) to (start + 1, 14)
+- Code(Counter(1)) at (prev + 2, 1) to (start + 0, 2)
+Highest counter ID seen: c1
+
+Function name: async_closure::main
+Raw bytes (14): 0x[01, 01, 00, 02, 01, 0b, 01, 01, 16, 01, 02, 05, 02, 02]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 0
+Number of file 0 mappings: 2
+- Code(Counter(0)) at (prev + 11, 1) to (start + 1, 22)
+- Code(Counter(0)) at (prev + 2, 5) to (start + 2, 2)
+Highest counter ID seen: c0
+
+Function name: async_closure::main::{closure#0}
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 0c, 23, 00, 24]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 0
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 12, 35) to (start + 0, 36)
+Highest counter ID seen: c0
+
+Function name: async_closure::main::{closure#0}::{closure#0}::<i16>
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 0c, 22, 00, 24]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 0
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 12, 34) to (start + 0, 36)
+Highest counter ID seen: c0
+
+Function name: async_closure::main::{closure#0}::{closure#1}::<i32>
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 0c, 23, 00, 24]
+Number of files: 1
+- file 0 => global file 1
+Number of expressions: 0
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 12, 35) to (start + 0, 36)
+Highest counter ID seen: c0
+
diff --git a/tests/coverage/async_closure.coverage b/tests/coverage/async_closure.coverage
new file mode 100644
index 00000000000..fd6edf7c29e
--- /dev/null
+++ b/tests/coverage/async_closure.coverage
@@ -0,0 +1,24 @@
+   LL|       |#![feature(async_closure)]
+   LL|       |//@ edition: 2021
+   LL|       |
+   LL|       |//@ aux-build: executor.rs
+   LL|       |extern crate executor;
+   LL|       |
+   LL|      1|async fn call_once(f: impl async FnOnce()) {
+   LL|      1|    f().await;
+   LL|      1|}
+   LL|       |
+   LL|      1|pub fn main() {
+   LL|      2|    let async_closure = async || {};
+                                               ^1
+  ------------------
+  | async_closure::main::{closure#0}:
+  |   LL|      1|    let async_closure = async || {};
+  ------------------
+  | async_closure::main::{closure#0}::{closure#1}::<i32>:
+  |   LL|      1|    let async_closure = async || {};
+  ------------------
+   LL|      1|    executor::block_on(async_closure());
+   LL|      1|    executor::block_on(call_once(async_closure));
+   LL|      1|}
+
diff --git a/tests/coverage/async_closure.rs b/tests/coverage/async_closure.rs
new file mode 100644
index 00000000000..c076d03eef4
--- /dev/null
+++ b/tests/coverage/async_closure.rs
@@ -0,0 +1,15 @@
+#![feature(async_closure)]
+//@ edition: 2021
+
+//@ aux-build: executor.rs
+extern crate executor;
+
+async fn call_once(f: impl async FnOnce()) {
+    f().await;
+}
+
+pub fn main() {
+    let async_closure = async || {};
+    executor::block_on(async_closure());
+    executor::block_on(call_once(async_closure));
+}
diff --git a/tests/crashes/131190.rs b/tests/crashes/131190.rs
deleted file mode 100644
index 3a0e64c69d5..00000000000
--- a/tests/crashes/131190.rs
+++ /dev/null
@@ -1,19 +0,0 @@
-//@ known-bug: #131190
-//@ compile-flags: -Cinstrument-coverage --edition=2018
-
-use std::future::Future;
-
-pub fn block_on<T>(fut: impl Future<Output = T>) -> T {}
-
-async fn call_once(f: impl async FnOnce(DropMe)) {
-    f(DropMe("world")).await;
-}
-
-struct DropMe(&'static str);
-
-pub fn main() {
-    block_on(async {
-        let async_closure = async move |a: DropMe| {};
-        call_once(async_closure).await;
-    });
-}
diff --git a/tests/run-make/avr-rjmp-offset/avr-rjmp-offsets.rs b/tests/run-make/avr-rjmp-offset/avr-rjmp-offsets.rs
new file mode 100644
index 00000000000..2f97fc1ed95
--- /dev/null
+++ b/tests/run-make/avr-rjmp-offset/avr-rjmp-offsets.rs
@@ -0,0 +1,47 @@
+//! This test case is a `#![no_core]`-version of the MVCE presented in #129301.
+//!
+//! The function [`delay()`] is removed, as it is not necessary to trigger the
+//! wrong behavior and would require some additional lang items.
+#![feature(no_core, lang_items, intrinsics, rustc_attrs)]
+#![no_core]
+#![no_main]
+#![allow(internal_features)]
+
+use minicore::ptr;
+
+#[no_mangle]
+pub fn main() -> ! {
+    let port_b = 0x25 as *mut u8; // the I/O-address of PORTB
+
+    // a simple loop with some trivial instructions within. This loop label has
+    // to be placed correctly before the `ptr::write_volatile()` (some LLVM ver-
+    // sions did place it after the first loop instruction, causing unsoundness)
+    loop {
+        unsafe { ptr::write_volatile(port_b, 1) };
+        unsafe { ptr::write_volatile(port_b, 2) };
+    }
+}
+
+// FIXME: replace with proper minicore once available (#130693)
+mod minicore {
+    #[lang = "sized"]
+    pub trait Sized {}
+
+    #[lang = "copy"]
+    pub trait Copy {}
+    impl Copy for u32 {}
+    impl Copy for &u32 {}
+    impl<T: ?Sized> Copy for *mut T {}
+
+    pub mod ptr {
+        #[inline]
+        #[rustc_diagnostic_item = "ptr_write_volatile"]
+        pub unsafe fn write_volatile<T>(dst: *mut T, src: T) {
+            extern "rust-intrinsic" {
+                #[rustc_nounwind]
+                pub fn volatile_store<T>(dst: *mut T, val: T);
+            }
+            unsafe { volatile_store(dst, src) };
+        }
+    }
+}
diff --git a/tests/run-make/avr-rjmp-offset/rmake.rs b/tests/run-make/avr-rjmp-offset/rmake.rs
new file mode 100644
index 00000000000..89cbca309be
--- /dev/null
+++ b/tests/run-make/avr-rjmp-offset/rmake.rs
@@ -0,0 +1,60 @@
+//@ needs-llvm-components: avr
+//@ needs-rust-lld
+//! Regression test for #129301/llvm-project#106722 within `rustc`.
+//!
+//! Some LLVM-versions had wrong offsets in the local labels, causing the first
+//! loop instruction to be missed. This test therefore contains a simple loop
+//! with trivial instructions in it, to see, where the label is placed.
+//!
+//! This must be a `rmake`-test and cannot be a `tests/assembly`-test, since the
+//! wrong output is only produced with direct assembly generation, but not when
+//! "emit-asm" is used, as described in the issue description of #129301:
+//! https://github.com/rust-lang/rust/issues/129301#issue-2475070770
+use run_make_support::{llvm_objdump, rustc};
+
+fn main() {
+    rustc()
+        .input("avr-rjmp-offsets.rs")
+        .opt_level("s")
+        .panic("abort")
+        .target("avr-unknown-gnu-atmega328")
+        // normally one links with `avr-gcc`, but this is not available in CI,
+        // hence this test diverges from the default behavior to enable linking
+        // at all, which is necessary for the test (to resolve the labels). To
+        // not depend on a special linker script, the main-function is marked as
+        // the entry function, causing the linker to not remove it.
+        .linker("rust-lld")
+        .link_arg("--entry=main")
+        .output("compiled")
+        .run();
+
+    let disassembly = llvm_objdump().disassemble().input("compiled").run().stdout_utf8();
+
+    // search for the following instruction sequence:
+    // ```disassembly
+    // 00000080 <main>:
+    // 80: 81 e0         ldi     r24, 0x1
+    // 82: 92 e0         ldi     r25, 0x2
+    // 84: 85 b9         out     0x5, r24
+    // 86: 95 b9         out     0x5, r25
+    // 88: fd cf         rjmp    .-6
+    // ```
+    // This matches on all instructions, since the size of the instructions be-
+    // fore the relative jump has an impact on the label offset. Old versions
+    // of the Rust compiler did produce a label `rjmp .-4` (misses the first
+    // instruction in the loop).
+    assert!(disassembly.contains("<main>"), "no main function in output");
+    disassembly
+        .trim()
+        .lines()
+        .skip_while(|&line| !line.contains("<main>"))
+        .inspect(|line| println!("{line}"))
+        .skip(1)
+        .zip(["ldi\t", "ldi\t", "out\t", "out\t", "rjmp\t.-6"])
+        .for_each(|(line, expected_instruction)| {
+            assert!(
+                line.contains(expected_instruction),
+                "expected instruction `{expected_instruction}`, got `{line}`"
+            );
+        });
+}
diff --git a/tests/ui/command/command-exec.rs b/tests/ui/command/command-exec.rs
index c97b8561410..d2545b0b472 100644
--- a/tests/ui/command/command-exec.rs
+++ b/tests/ui/command/command-exec.rs
@@ -26,23 +26,23 @@ fn main() {
             }
 
             "exec-test2" => {
-                Command::new("/path/to/nowhere").exec();
+                let _ = Command::new("/path/to/nowhere").exec();
                 println!("passed");
             }
 
             "exec-test3" => {
-                Command::new(&me).arg("bad\0").exec();
+                let _ = Command::new(&me).arg("bad\0").exec();
                 println!("passed");
             }
 
             "exec-test4" => {
-                Command::new(&me).current_dir("/path/to/nowhere").exec();
+                let _ = Command::new(&me).current_dir("/path/to/nowhere").exec();
                 println!("passed");
             }
 
             "exec-test5" => {
                 env::set_var("VARIABLE", "ABC");
-                Command::new("definitely-not-a-real-binary").env("VARIABLE", "XYZ").exec();
+                let _ =  Command::new("definitely-not-a-real-binary").env("VARIABLE", "XYZ").exec();
                 assert_eq!(env::var("VARIABLE").unwrap(), "ABC");
                 println!("passed");
             }
diff --git a/tests/ui/impl-trait/unsized_coercion5.next.stderr b/tests/ui/impl-trait/unsized_coercion5.next.stderr
deleted file mode 100644
index 5644ac7ab04..00000000000
--- a/tests/ui/impl-trait/unsized_coercion5.next.stderr
+++ /dev/null
@@ -1,14 +0,0 @@
-error[E0308]: mismatched types
-  --> $DIR/unsized_coercion5.rs:16:32
-   |
-LL |         let y: Box<dyn Send> = x as Box<dyn Trait + Send>;
-   |                -------------   ^^^^^^^^^^^^^^^^^^^^^^^^^^ expected trait `Send`, found trait `Trait + Send`
-   |                |
-   |                expected due to this
-   |
-   = note: expected struct `Box<dyn Send>`
-              found struct `Box<dyn Trait + Send>`
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0308`.
diff --git a/tests/ui/impl-trait/unsized_coercion5.old.stderr b/tests/ui/impl-trait/unsized_coercion5.old.stderr
index 06ad54b1f1d..e56c026b037 100644
--- a/tests/ui/impl-trait/unsized_coercion5.old.stderr
+++ b/tests/ui/impl-trait/unsized_coercion5.old.stderr
@@ -1,16 +1,5 @@
-error[E0308]: mismatched types
-  --> $DIR/unsized_coercion5.rs:16:32
-   |
-LL |         let y: Box<dyn Send> = x as Box<dyn Trait + Send>;
-   |                -------------   ^^^^^^^^^^^^^^^^^^^^^^^^^^ expected trait `Send`, found trait `Trait + Send`
-   |                |
-   |                expected due to this
-   |
-   = note: expected struct `Box<dyn Send>`
-              found struct `Box<dyn Trait + Send>`
-
 error[E0277]: the size for values of type `impl Trait + ?Sized` cannot be known at compilation time
-  --> $DIR/unsized_coercion5.rs:16:32
+  --> $DIR/unsized_coercion5.rs:17:32
    |
 LL |         let y: Box<dyn Send> = x as Box<dyn Trait + Send>;
    |                                ^ doesn't have a size known at compile-time
@@ -18,7 +7,6 @@ LL |         let y: Box<dyn Send> = x as Box<dyn Trait + Send>;
    = help: the trait `Sized` is not implemented for `impl Trait + ?Sized`
    = note: required for the cast from `Box<impl Trait + ?Sized>` to `Box<dyn Trait + Send>`
 
-error: aborting due to 2 previous errors
+error: aborting due to 1 previous error
 
-Some errors have detailed explanations: E0277, E0308.
-For more information about an error, try `rustc --explain E0277`.
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/impl-trait/unsized_coercion5.rs b/tests/ui/impl-trait/unsized_coercion5.rs
index 85d313caa13..81f8a6afe9a 100644
--- a/tests/ui/impl-trait/unsized_coercion5.rs
+++ b/tests/ui/impl-trait/unsized_coercion5.rs
@@ -3,6 +3,7 @@
 
 //@ revisions: next old
 //@[next] compile-flags: -Znext-solver
+//@[next] check-pass
 
 #![feature(trait_upcasting)]
 
@@ -15,7 +16,6 @@ fn hello() -> Box<impl Trait + ?Sized> {
         let x = hello();
         let y: Box<dyn Send> = x as Box<dyn Trait + Send>;
         //[old]~^ ERROR: the size for values of type `impl Trait + ?Sized` cannot be know
-        //~^^ ERROR: mismatched types
     }
     Box::new(1u32)
 }
diff --git a/tests/ui/traits/dyn-drop-principal.rs b/tests/ui/traits/dyn-drop-principal.rs
new file mode 100644
index 00000000000..c233127e43d
--- /dev/null
+++ b/tests/ui/traits/dyn-drop-principal.rs
@@ -0,0 +1,68 @@
+//@ run-pass
+//@ check-run-results
+
+use std::{alloc::Layout, any::Any};
+
+const fn yeet_principal(x: Box<dyn Any + Send>) -> Box<dyn Send> {
+    x
+}
+
+trait Bar: Send + Sync {}
+
+impl<T: Send + Sync> Bar for T {}
+
+const fn yeet_principal_2(x: Box<dyn Bar>) -> Box<dyn Send> {
+    x
+}
+
+struct CallMe<F: FnOnce()>(Option<F>);
+
+impl<F: FnOnce()> CallMe<F> {
+    fn new(f: F) -> Self {
+        CallMe(Some(f))
+    }
+}
+
+impl<F: FnOnce()> Drop for CallMe<F> {
+    fn drop(&mut self) {
+        (self.0.take().unwrap())();
+    }
+}
+
+fn goodbye() {
+    println!("goodbye");
+}
+
+fn main() {
+    let x = Box::new(CallMe::new(goodbye)) as Box<dyn Any + Send>;
+    let x_layout = Layout::for_value(&*x);
+    let y = yeet_principal(x);
+    let y_layout = Layout::for_value(&*y);
+    assert_eq!(x_layout, y_layout);
+    println!("before");
+    drop(y);
+
+    let x = Box::new(CallMe::new(goodbye)) as Box<dyn Bar>;
+    let x_layout = Layout::for_value(&*x);
+    let y = yeet_principal_2(x);
+    let y_layout = Layout::for_value(&*y);
+    assert_eq!(x_layout, y_layout);
+    println!("before");
+    drop(y);
+}
+
+// Test that upcast works in `const`
+
+const fn yeet_principal_3(x: &(dyn Any + Send + Sync)) -> &(dyn Send + Sync) {
+    x
+}
+
+#[used]
+pub static FOO: &(dyn Send + Sync) = yeet_principal_3(&false);
+
+const fn yeet_principal_4(x: &dyn Bar) -> &(dyn Send + Sync) {
+    x
+}
+
+#[used]
+pub static BAR: &(dyn Send + Sync) = yeet_principal_4(&false);
diff --git a/tests/ui/traits/dyn-drop-principal.run.stdout b/tests/ui/traits/dyn-drop-principal.run.stdout
new file mode 100644
index 00000000000..edd99a114a1
--- /dev/null
+++ b/tests/ui/traits/dyn-drop-principal.run.stdout
@@ -0,0 +1,4 @@
+before
+goodbye
+before
+goodbye
diff --git a/tests/ui/traits/dyn-star-drop-principal.rs b/tests/ui/traits/dyn-star-drop-principal.rs
new file mode 100644
index 00000000000..1ad99070339
--- /dev/null
+++ b/tests/ui/traits/dyn-star-drop-principal.rs
@@ -0,0 +1,12 @@
+#![feature(dyn_star)]
+#![allow(incomplete_features)]
+
+trait Trait {}
+impl Trait for usize {}
+
+fn main() {
+    // We allow &dyn Trait + Send -> &dyn Send (i.e. dropping principal),
+    // but we don't (currently?) allow the same for dyn*
+    let x: dyn* Trait + Send = 1usize;
+    x as dyn* Send; //~ error: `dyn* Trait + Send` needs to have the same ABI as a pointer
+}
diff --git a/tests/ui/traits/dyn-star-drop-principal.stderr b/tests/ui/traits/dyn-star-drop-principal.stderr
new file mode 100644
index 00000000000..721ae7e191e
--- /dev/null
+++ b/tests/ui/traits/dyn-star-drop-principal.stderr
@@ -0,0 +1,11 @@
+error[E0277]: `dyn* Trait + Send` needs to have the same ABI as a pointer
+  --> $DIR/dyn-star-drop-principal.rs:11:5
+   |
+LL |     x as dyn* Send;
+   |     ^ `dyn* Trait + Send` needs to be a pointer-like type
+   |
+   = help: the trait `PointerLike` is not implemented for `dyn* Trait + Send`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.