Auto merge of #146267 - matthiaskrgr:rollup-tbz7shx, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - rust-lang/rust#127316 (move pinned version from tracing_core to tracing)
 - rust-lang/rust#144801 (Suggest bounds in more cases, accounting for type parameters referenced in predicate)
 - rust-lang/rust#146211 (Disallow shebang in `--cfg` and `--check-cfg` arguments)
 - rust-lang/rust#146263 (Fix `bump-stage0` build failure, and check-build `bump-stage0` in CI)
 - rust-lang/rust#146266 (miri std tests: skip all of sys::)

r? `@ghost`
`@rustbot` modify labels: rollup

22 files changed, 232 insertions, 53 deletions

diff --git a/Cargo.lock b/Cargo.lock
index c4c96f1569b..09902936521 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -336,7 +336,7 @@ dependencies = [
  "curl",
  "indexmap",
  "serde",
- "toml 0.7.8",
+ "toml 0.8.23",
 ]
 
 [[package]]
@@ -4072,7 +4072,6 @@ name = "rustc_log"
 version = "0.0.0"
 dependencies = [
  "tracing",
- "tracing-core",
  "tracing-subscriber",
  "tracing-tree",
 ]
@@ -5541,9 +5540,9 @@ dependencies = [
 
 [[package]]
 name = "tracing-core"
-version = "0.1.30"
+version = "0.1.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "24eb03ba0eab1fd845050058ce5e616558e8f8d8fca633e6b163fe25c797213a"
+checksum = "b9d12581f227e93f094d3af2ae690a574abb8a2b9b7a96e7cfe9647b2b617678"
 dependencies = [
  "once_cell",
  "valuable",
diff --git a/compiler/rustc_log/Cargo.toml b/compiler/rustc_log/Cargo.toml
index c673d51a1d4..2332ff9b323 100644
--- a/compiler/rustc_log/Cargo.toml
+++ b/compiler/rustc_log/Cargo.toml
@@ -5,8 +5,8 @@ edition = "2024"
 
 [dependencies]
 # tidy-alphabetical-start
-tracing = "0.1.28"
-tracing-core = "=0.1.30" # FIXME(Nilstrieb) tracing has a deadlock: https://github.com/tokio-rs/tracing/issues/2635
+# tracing > 0.1.37 have huge binary size / instructions regression
+tracing = "=0.1.37"
 tracing-subscriber = { version = "0.3.3", default-features = false, features = ["fmt", "env-filter", "smallvec", "parking_lot", "ansi"] }
 tracing-tree = "0.3.1"
 # tidy-alphabetical-end
diff --git a/compiler/rustc_log/src/lib.rs b/compiler/rustc_log/src/lib.rs
index df648bbd489..26475eec1c1 100644
--- a/compiler/rustc_log/src/lib.rs
+++ b/compiler/rustc_log/src/lib.rs
@@ -38,7 +38,7 @@ use std::fmt::{self, Display};
 use std::io::{self, IsTerminal};
 
 use tracing::dispatcher::SetGlobalDefaultError;
-use tracing_core::{Event, Subscriber};
+use tracing::{Event, Subscriber};
 use tracing_subscriber::filter::{Directive, EnvFilter, LevelFilter};
 use tracing_subscriber::fmt::FmtContext;
 use tracing_subscriber::fmt::format::{self, FormatEvent, FormatFields};
diff --git a/compiler/rustc_parse/src/lexer/mod.rs b/compiler/rustc_parse/src/lexer/mod.rs
index e3bd6a9a327..f5f081efc49 100644
--- a/compiler/rustc_parse/src/lexer/mod.rs
+++ b/compiler/rustc_parse/src/lexer/mod.rs
@@ -44,19 +44,44 @@ pub(crate) struct UnmatchedDelim {
     pub candidate_span: Option<Span>,
 }
 
+/// Which tokens should be stripped before lexing the tokens.
+pub(crate) enum StripTokens {
+    /// Strip both shebang and frontmatter.
+    ShebangAndFrontmatter,
+    /// Strip the shebang but not frontmatter.
+    ///
+    /// That means that char sequences looking like frontmatter are simply
+    /// interpreted as regular Rust lexemes.
+    Shebang,
+    /// Strip nothing.
+    ///
+    /// In other words, char sequences looking like a shebang or frontmatter
+    /// are simply interpreted as regular Rust lexemes.
+    Nothing,
+}
+
 pub(crate) fn lex_token_trees<'psess, 'src>(
     psess: &'psess ParseSess,
     mut src: &'src str,
     mut start_pos: BytePos,
     override_span: Option<Span>,
-    frontmatter_allowed: FrontmatterAllowed,
+    strip_tokens: StripTokens,
 ) -> Result<TokenStream, Vec<Diag<'psess>>> {
-    // Skip `#!`, if present.
-    if let Some(shebang_len) = rustc_lexer::strip_shebang(src) {
-        src = &src[shebang_len..];
-        start_pos = start_pos + BytePos::from_usize(shebang_len);
+    match strip_tokens {
+        StripTokens::Shebang | StripTokens::ShebangAndFrontmatter => {
+            if let Some(shebang_len) = rustc_lexer::strip_shebang(src) {
+                src = &src[shebang_len..];
+                start_pos = start_pos + BytePos::from_usize(shebang_len);
+            }
+        }
+        StripTokens::Nothing => {}
     }
 
+    let frontmatter_allowed = match strip_tokens {
+        StripTokens::ShebangAndFrontmatter => FrontmatterAllowed::Yes,
+        StripTokens::Shebang | StripTokens::Nothing => FrontmatterAllowed::No,
+    };
+
     let cursor = Cursor::new(src, frontmatter_allowed);
     let mut lexer = Lexer {
         psess,
diff --git a/compiler/rustc_parse/src/lib.rs b/compiler/rustc_parse/src/lib.rs
index b790966acfd..d8792d7af4c 100644
--- a/compiler/rustc_parse/src/lib.rs
+++ b/compiler/rustc_parse/src/lib.rs
@@ -21,7 +21,6 @@ use rustc_ast::tokenstream::{DelimSpan, TokenStream};
 use rustc_ast::{AttrItem, Attribute, MetaItemInner, token};
 use rustc_ast_pretty::pprust;
 use rustc_errors::{Diag, EmissionGuarantee, FatalError, PResult, pluralize};
-use rustc_lexer::FrontmatterAllowed;
 use rustc_session::parse::ParseSess;
 use rustc_span::source_map::SourceMap;
 use rustc_span::{FileName, SourceFile, Span};
@@ -34,6 +33,8 @@ pub mod parser;
 use parser::Parser;
 use rustc_ast::token::Delimiter;
 
+use crate::lexer::StripTokens;
+
 pub mod lexer;
 
 mod errors;
@@ -62,10 +63,10 @@ pub fn new_parser_from_source_str(
     source: String,
 ) -> Result<Parser<'_>, Vec<Diag<'_>>> {
     let source_file = psess.source_map().new_source_file(name, source);
-    new_parser_from_source_file(psess, source_file, FrontmatterAllowed::Yes)
+    new_parser_from_source_file(psess, source_file, StripTokens::ShebangAndFrontmatter)
 }
 
-/// Creates a new parser from a simple (no frontmatter) source string.
+/// Creates a new parser from a simple (no shebang, no frontmatter) source string.
 ///
 /// On failure, the errors must be consumed via `unwrap_or_emit_fatal`, `emit`, `cancel`,
 /// etc., otherwise a panic will occur when they are dropped.
@@ -75,7 +76,7 @@ pub fn new_parser_from_simple_source_str(
     source: String,
 ) -> Result<Parser<'_>, Vec<Diag<'_>>> {
     let source_file = psess.source_map().new_source_file(name, source);
-    new_parser_from_source_file(psess, source_file, FrontmatterAllowed::No)
+    new_parser_from_source_file(psess, source_file, StripTokens::Nothing)
 }
 
 /// Creates a new parser from a filename. On failure, the errors must be consumed via
@@ -109,7 +110,7 @@ pub fn new_parser_from_file<'a>(
         }
         err.emit();
     });
-    new_parser_from_source_file(psess, source_file, FrontmatterAllowed::Yes)
+    new_parser_from_source_file(psess, source_file, StripTokens::ShebangAndFrontmatter)
 }
 
 pub fn utf8_error<E: EmissionGuarantee>(
@@ -160,10 +161,10 @@ pub fn utf8_error<E: EmissionGuarantee>(
 fn new_parser_from_source_file(
     psess: &ParseSess,
     source_file: Arc<SourceFile>,
-    frontmatter_allowed: FrontmatterAllowed,
+    strip_tokens: StripTokens,
 ) -> Result<Parser<'_>, Vec<Diag<'_>>> {
     let end_pos = source_file.end_position();
-    let stream = source_file_to_stream(psess, source_file, None, frontmatter_allowed)?;
+    let stream = source_file_to_stream(psess, source_file, None, strip_tokens)?;
     let mut parser = Parser::new(psess, stream, None);
     if parser.token == token::Eof {
         parser.token.span = Span::new(end_pos, end_pos, parser.token.span.ctxt(), None);
@@ -179,8 +180,8 @@ pub fn source_str_to_stream(
 ) -> Result<TokenStream, Vec<Diag<'_>>> {
     let source_file = psess.source_map().new_source_file(name, source);
     // used mainly for `proc_macro` and the likes, not for our parsing purposes, so don't parse
-    // frontmatters as frontmatters.
-    source_file_to_stream(psess, source_file, override_span, FrontmatterAllowed::No)
+    // frontmatters as frontmatters, but for compatibility reason still strip the shebang
+    source_file_to_stream(psess, source_file, override_span, StripTokens::Shebang)
 }
 
 /// Given a source file, produces a sequence of token trees. Returns any buffered errors from
@@ -189,7 +190,7 @@ fn source_file_to_stream<'psess>(
     psess: &'psess ParseSess,
     source_file: Arc<SourceFile>,
     override_span: Option<Span>,
-    frontmatter_allowed: FrontmatterAllowed,
+    strip_tokens: StripTokens,
 ) -> Result<TokenStream, Vec<Diag<'psess>>> {
     let src = source_file.src.as_ref().unwrap_or_else(|| {
         psess.dcx().bug(format!(
@@ -198,13 +199,7 @@ fn source_file_to_stream<'psess>(
         ));
     });
 
-    lexer::lex_token_trees(
-        psess,
-        src.as_str(),
-        source_file.start_pos,
-        override_span,
-        frontmatter_allowed,
-    )
+    lexer::lex_token_trees(psess, src.as_str(), source_file.start_pos, override_span, strip_tokens)
 }
 
 /// Runs the given subparser `f` on the tokens of the given `attr`'s item.
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
index 40a27c9aebe..f6dbbeb51ca 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
@@ -32,8 +32,8 @@ use rustc_middle::ty::print::{
 };
 use rustc_middle::ty::{
     self, AdtKind, GenericArgs, InferTy, IsSuggestable, Ty, TyCtxt, TypeFoldable, TypeFolder,
-    TypeSuperFoldable, TypeVisitableExt, TypeckResults, Upcast, suggest_arbitrary_trait_bound,
-    suggest_constraining_type_param,
+    TypeSuperFoldable, TypeSuperVisitable, TypeVisitableExt, TypeVisitor, TypeckResults, Upcast,
+    suggest_arbitrary_trait_bound, suggest_constraining_type_param,
 };
 use rustc_middle::{bug, span_bug};
 use rustc_span::def_id::LocalDefId;
@@ -263,6 +263,9 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             _ => (false, None),
         };
 
+        let mut finder = ParamFinder { .. };
+        finder.visit_binder(&trait_pred);
+
         // FIXME: Add check for trait bound that is already present, particularly `?Sized` so we
         //        don't suggest `T: Sized + ?Sized`.
         loop {
@@ -411,6 +414,26 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                     }
                 }
 
+                hir::Node::TraitItem(hir::TraitItem {
+                    generics,
+                    kind: hir::TraitItemKind::Fn(..),
+                    ..
+                })
+                | hir::Node::ImplItem(hir::ImplItem {
+                    generics,
+                    trait_item_def_id: None,
+                    kind: hir::ImplItemKind::Fn(..),
+                    ..
+                }) if finder.can_suggest_bound(generics) => {
+                    // Missing generic type parameter bound.
+                    suggest_arbitrary_trait_bound(
+                        self.tcx,
+                        generics,
+                        err,
+                        trait_pred,
+                        associated_ty,
+                    );
+                }
                 hir::Node::Item(hir::Item {
                     kind:
                         hir::ItemKind::Struct(_, generics, _)
@@ -423,7 +446,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                         | hir::ItemKind::Const(_, generics, _, _)
                         | hir::ItemKind::TraitAlias(_, generics, _),
                     ..
-                }) if !param_ty => {
+                }) if finder.can_suggest_bound(generics) => {
                     // Missing generic type parameter bound.
                     if suggest_arbitrary_trait_bound(
                         self.tcx,
@@ -5068,8 +5091,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         // Suggesting `T: ?Sized` is only valid in an ADT if `T` is only used in a
         // borrow. `struct S<'a, T: ?Sized>(&'a T);` is valid, `struct S<T: ?Sized>(T);`
         // is not. Look for invalid "bare" parameter uses, and suggest using indirection.
-        let mut visitor =
-            FindTypeParam { param: param.name.ident().name, invalid_spans: vec![], nested: false };
+        let mut visitor = FindTypeParam { param: param.name.ident().name, .. };
         visitor.visit_item(item);
         if visitor.invalid_spans.is_empty() {
             return false;
@@ -5228,7 +5250,7 @@ fn hint_missing_borrow<'tcx>(
 /// Used to suggest replacing associated types with an explicit type in `where` clauses.
 #[derive(Debug)]
 pub struct SelfVisitor<'v> {
-    pub paths: Vec<&'v hir::Ty<'v>>,
+    pub paths: Vec<&'v hir::Ty<'v>> = Vec::new(),
     pub name: Option<Symbol>,
 }
 
@@ -5599,7 +5621,7 @@ fn point_at_assoc_type_restriction<G: EmissionGuarantee>(
                 );
                 // Search for the associated type `Self::{name}`, get
                 // its type and suggest replacing the bound with it.
-                let mut visitor = SelfVisitor { paths: vec![], name: Some(name) };
+                let mut visitor = SelfVisitor { name: Some(name), .. };
                 visitor.visit_trait_ref(trait_ref);
                 for path in visitor.paths {
                     err.span_suggestion_verbose(
@@ -5610,7 +5632,7 @@ fn point_at_assoc_type_restriction<G: EmissionGuarantee>(
                     );
                 }
             } else {
-                let mut visitor = SelfVisitor { paths: vec![], name: None };
+                let mut visitor = SelfVisitor { name: None, .. };
                 visitor.visit_trait_ref(trait_ref);
                 let span: MultiSpan =
                     visitor.paths.iter().map(|p| p.span).collect::<Vec<Span>>().into();
@@ -5640,8 +5662,8 @@ fn get_deref_type_and_refs(mut ty: Ty<'_>) -> (Ty<'_>, Vec<hir::Mutability>) {
 /// `param: ?Sized` would be a valid constraint.
 struct FindTypeParam {
     param: rustc_span::Symbol,
-    invalid_spans: Vec<Span>,
-    nested: bool,
+    invalid_spans: Vec<Span> = Vec::new(),
+    nested: bool = false,
 }
 
 impl<'v> Visitor<'v> for FindTypeParam {
@@ -5679,3 +5701,38 @@ impl<'v> Visitor<'v> for FindTypeParam {
         }
     }
 }
+
+/// Look for type parameters in predicates. We use this to identify whether a bound is suitable in
+/// on a given item.
+struct ParamFinder {
+    params: Vec<Symbol> = Vec::new(),
+}
+
+impl<'tcx> TypeVisitor<TyCtxt<'tcx>> for ParamFinder {
+    fn visit_ty(&mut self, t: Ty<'tcx>) -> Self::Result {
+        match t.kind() {
+            ty::Param(p) => self.params.push(p.name),
+            _ => {}
+        }
+        t.super_visit_with(self)
+    }
+}
+
+impl ParamFinder {
+    /// Whether the `hir::Generics` of the current item can suggest the evaluated bound because its
+    /// references to type parameters are present in the generics.
+    fn can_suggest_bound(&self, generics: &hir::Generics<'_>) -> bool {
+        if self.params.is_empty() {
+            // There are no references to type parameters at all, so suggesting the bound
+            // would be reasonable.
+            return true;
+        }
+        generics.params.iter().any(|p| match p.name {
+            hir::ParamName::Plain(p_name) => {
+                // All of the parameters in the bound can be referenced in the current item.
+                self.params.iter().any(|p| *p == p_name.name || *p == kw::SelfUpper)
+            }
+            _ => true,
+        })
+    }
+}
diff --git a/compiler/rustc_trait_selection/src/lib.rs b/compiler/rustc_trait_selection/src/lib.rs
index e2b22f7bab7..fc0cf8f140a 100644
--- a/compiler/rustc_trait_selection/src/lib.rs
+++ b/compiler/rustc_trait_selection/src/lib.rs
@@ -19,6 +19,7 @@
 #![feature(assert_matches)]
 #![feature(associated_type_defaults)]
 #![feature(box_patterns)]
+#![feature(default_field_values)]
 #![feature(if_let_guard)]
 #![feature(iter_intersperse)]
 #![feature(iterator_try_reduce)]
diff --git a/src/bootstrap/mk/Makefile.in b/src/bootstrap/mk/Makefile.in
index 82c05092dfa..03caa764ccf 100644
--- a/src/bootstrap/mk/Makefile.in
+++ b/src/bootstrap/mk/Makefile.in
@@ -76,7 +76,7 @@ check-aux:
 		library/std \
 		$(BOOTSTRAP_ARGS) \
 		-- \
-		--skip fs:: --skip net:: --skip process:: --skip sys::fd:: --skip sys::pal::
+		--skip fs:: --skip net:: --skip process:: --skip sys::
 	# Also test some very target-specific modules on other targets
 	# (making sure to cover an i686 target as well).
 	$(Q)MIRIFLAGS="-Zmiri-disable-isolation" BOOTSTRAP_SKIP_TARGET_SANITY=1 \
diff --git a/src/bootstrap/src/core/build_steps/check.rs b/src/bootstrap/src/core/build_steps/check.rs
index 49d12b64da5..043457f64e5 100644
--- a/src/bootstrap/src/core/build_steps/check.rs
+++ b/src/bootstrap/src/core/build_steps/check.rs
@@ -839,3 +839,9 @@ tool_check_step!(Linkchecker {
     mode: |_builder| Mode::ToolBootstrap,
     default: false
 });
+
+tool_check_step!(BumpStage0 {
+    path: "src/tools/bump-stage0",
+    mode: |_builder| Mode::ToolBootstrap,
+    default: false
+});
diff --git a/src/bootstrap/src/core/builder/mod.rs b/src/bootstrap/src/core/builder/mod.rs
index 627085df812..a818a5c756c 100644
--- a/src/bootstrap/src/core/builder/mod.rs
+++ b/src/bootstrap/src/core/builder/mod.rs
@@ -1061,6 +1061,7 @@ impl<'a> Builder<'a> {
                 check::FeaturesStatusDump,
                 check::CoverageDump,
                 check::Linkchecker,
+                check::BumpStage0,
                 // This has special staging logic, it may run on stage 1 while others run on stage 0.
                 // It takes quite some time to build stage 1, so put this at the end.
                 //
diff --git a/src/ci/docker/host-x86_64/pr-check-2/Dockerfile b/src/ci/docker/host-x86_64/pr-check-2/Dockerfile
index 8073b8efb46..d6470e4deb8 100644
--- a/src/ci/docker/host-x86_64/pr-check-2/Dockerfile
+++ b/src/ci/docker/host-x86_64/pr-check-2/Dockerfile
@@ -28,6 +28,7 @@ RUN sh /scripts/sccache.sh
 
 ENV SCRIPT \
         python3 ../x.py check && \
+        python3 ../x.py check src/tools/bump-stage0 && \
         python3 ../x.py clippy ci --stage 2 && \
         python3 ../x.py test --stage 1 core alloc std test proc_macro && \
         python3 ../x.py test --stage 1 src/tools/compiletest && \
diff --git a/src/tools/bump-stage0/Cargo.toml b/src/tools/bump-stage0/Cargo.toml
index b7f3625da91..79097f2c189 100644
--- a/src/tools/bump-stage0/Cargo.toml
+++ b/src/tools/bump-stage0/Cargo.toml
@@ -11,4 +11,4 @@ build_helper = { path = "../../build_helper" }
 curl = "0.4.38"
 indexmap = { version = "2.0.0", features = ["serde"] }
 serde = { version = "1.0.125", features = ["derive"] }
-toml = "0.7"
+toml = "0.8.23"
diff --git a/src/tools/bump-stage0/src/main.rs b/src/tools/bump-stage0/src/main.rs
index 680437cce4f..faed748785f 100644
--- a/src/tools/bump-stage0/src/main.rs
+++ b/src/tools/bump-stage0/src/main.rs
@@ -185,7 +185,11 @@ fn fetch_manifest(
         format!("{}/dist/channel-rust-{}.toml", config.dist_server, channel)
     };
 
-    Ok(toml::from_slice(&http_get(&url)?)?)
+    // FIXME: on newer `toml` (>= `0.9.*`), use `toml::from_slice`. For now, we use the most recent
+    // `toml` available in-tree which is `0.8.*`, so we have to do an additional dance here.
+    let response = http_get(&url)?;
+    let response = String::from_utf8(response)?;
+    Ok(toml::from_str(&response)?)
 }
 
 fn http_get(url: &str) -> Result<Vec<u8>, Error> {
diff --git a/tests/run-make/multiline-args-value/cfg.stderr b/tests/run-make/multiline-args-value/cfg-frontmatter.stderr
index 9b06f84be48..9b06f84be48 100644
--- a/tests/run-make/multiline-args-value/cfg.stderr
+++ b/tests/run-make/multiline-args-value/cfg-frontmatter.stderr
diff --git a/tests/run-make/multiline-args-value/cfg-shebang.stderr b/tests/run-make/multiline-args-value/cfg-shebang.stderr
new file mode 100644
index 00000000000..09baf3b5123
--- /dev/null
+++ b/tests/run-make/multiline-args-value/cfg-shebang.stderr
@@ -0,0 +1,3 @@
+error: invalid `--cfg` argument: `#!/usr/bin/shebang
+       key` (expected `key` or `key="value"`)
+
diff --git a/tests/run-make/multiline-args-value/check-cfg.stderr b/tests/run-make/multiline-args-value/check-cfg-frontmatter.stderr
index 4a499cc0a1e..4a499cc0a1e 100644
--- a/tests/run-make/multiline-args-value/check-cfg.stderr
+++ b/tests/run-make/multiline-args-value/check-cfg-frontmatter.stderr
diff --git a/tests/run-make/multiline-args-value/check-cfg-shebang.stderr b/tests/run-make/multiline-args-value/check-cfg-shebang.stderr
new file mode 100644
index 00000000000..5bf18dc2b14
--- /dev/null
+++ b/tests/run-make/multiline-args-value/check-cfg-shebang.stderr
@@ -0,0 +1,6 @@
+error: invalid `--check-cfg` argument: `#!/usr/bin/shebang
+       cfg(key)`
+  |
+  = note: expected `cfg(name, values("value1", "value2", ... "valueN"))`
+  = note: visit <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more details
+
diff --git a/tests/run-make/multiline-args-value/rmake.rs b/tests/run-make/multiline-args-value/rmake.rs
index 825cbd158c0..3964cbbc1e6 100644
--- a/tests/run-make/multiline-args-value/rmake.rs
+++ b/tests/run-make/multiline-args-value/rmake.rs
@@ -1,15 +1,14 @@
 use run_make_support::{cwd, diff, rustc};
 
-fn test_and_compare(flag: &str, val: &str) {
+fn test_and_compare(test_name: &str, flag: &str, val: &str) {
     let mut cmd = rustc();
 
-    let output =
-        cmd.input("").arg("--crate-type=lib").arg(&format!("--{flag}")).arg(val).run_fail();
+    let output = cmd.input("").arg("--crate-type=lib").arg(flag).arg(val).run_fail();
 
     assert_eq!(output.stdout_utf8(), "");
     diff()
-        .expected_file(format!("{flag}.stderr"))
-        .actual_text("output", output.stderr_utf8())
+        .expected_file(format!("{test_name}.stderr"))
+        .actual_text("stderr", output.stderr_utf8())
         .run();
 }
 
@@ -17,7 +16,8 @@ fn main() {
     // Verify that frontmatter isn't allowed in `--cfg` arguments.
     // https://github.com/rust-lang/rust/issues/146130
     test_and_compare(
-        "cfg",
+        "cfg-frontmatter",
+        "--cfg",
         r#"---
 ---
 key"#,
@@ -26,9 +26,26 @@ key"#,
     // Verify that frontmatter isn't allowed in `--check-cfg` arguments.
     // https://github.com/rust-lang/rust/issues/146130
     test_and_compare(
-        "check-cfg",
+        "check-cfg-frontmatter",
+        "--check-cfg",
         r#"---
 ---
 cfg(key)"#,
     );
+
+    // Verify that shebang isn't allowed in `--cfg` arguments.
+    test_and_compare(
+        "cfg-shebang",
+        "--cfg",
+        r#"#!/usr/bin/shebang
+key"#,
+    );
+
+    // Verify that shebang isn't allowed in `--check-cfg` arguments.
+    test_and_compare(
+        "check-cfg-shebang",
+        "--check-cfg",
+        r#"#!/usr/bin/shebang
+cfg(key)"#,
+    );
 }
diff --git a/tests/ui/const-generics/failing_goal_with_repeat_expr_anon_const.stderr b/tests/ui/const-generics/failing_goal_with_repeat_expr_anon_const.stderr
index 12de4f1dc30..cf5b55a0ce2 100644
--- a/tests/ui/const-generics/failing_goal_with_repeat_expr_anon_const.stderr
+++ b/tests/ui/const-generics/failing_goal_with_repeat_expr_anon_const.stderr
@@ -21,10 +21,6 @@ LL |         [0u8; std::mem::size_of::<Self::A>()] == Self::P;
    |                                               ^^ no implementation for `[u8; std::mem::size_of::<Self::A>()] == <Self as T>::A`
    |
    = help: the trait `PartialEq<<Self as T>::A>` is not implemented for `[u8; std::mem::size_of::<Self::A>()]`
-help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
-   |
-LL | pub trait T where [u8; std::mem::size_of::<Self::A>()]: PartialEq<<Self as T>::A> {
-   |             +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
 error: aborting due to 3 previous errors
 
diff --git a/tests/ui/traits/bound/suggest-complex-bound-on-method.fixed b/tests/ui/traits/bound/suggest-complex-bound-on-method.fixed
new file mode 100644
index 00000000000..719835af0a9
--- /dev/null
+++ b/tests/ui/traits/bound/suggest-complex-bound-on-method.fixed
@@ -0,0 +1,23 @@
+//@ run-rustfix
+#![allow(dead_code)]
+struct Application;
+// https://github.com/rust-lang/rust/issues/144734
+trait Trait {
+    type Error: std::error::Error;
+
+    fn run(&self) -> Result<(), Self::Error>;
+}
+
+#[derive(Debug)]
+enum ApplicationError {
+    Quit,
+}
+
+impl Application {
+    fn thing<T: Trait>(&self, t: T) -> Result<(), ApplicationError> where ApplicationError: From<<T as Trait>::Error> {
+        t.run()?; //~ ERROR E0277
+        Ok(())
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/traits/bound/suggest-complex-bound-on-method.rs b/tests/ui/traits/bound/suggest-complex-bound-on-method.rs
new file mode 100644
index 00000000000..39cec571242
--- /dev/null
+++ b/tests/ui/traits/bound/suggest-complex-bound-on-method.rs
@@ -0,0 +1,23 @@
+//@ run-rustfix
+#![allow(dead_code)]
+struct Application;
+// https://github.com/rust-lang/rust/issues/144734
+trait Trait {
+    type Error: std::error::Error;
+
+    fn run(&self) -> Result<(), Self::Error>;
+}
+
+#[derive(Debug)]
+enum ApplicationError {
+    Quit,
+}
+
+impl Application {
+    fn thing<T: Trait>(&self, t: T) -> Result<(), ApplicationError> {
+        t.run()?; //~ ERROR E0277
+        Ok(())
+    }
+}
+
+fn main() {}
diff --git a/tests/ui/traits/bound/suggest-complex-bound-on-method.stderr b/tests/ui/traits/bound/suggest-complex-bound-on-method.stderr
new file mode 100644
index 00000000000..ac45f049541
--- /dev/null
+++ b/tests/ui/traits/bound/suggest-complex-bound-on-method.stderr
@@ -0,0 +1,22 @@
+error[E0277]: `?` couldn't convert the error to `ApplicationError`
+  --> $DIR/suggest-complex-bound-on-method.rs:18:16
+   |
+LL |         t.run()?;
+   |           -----^ the trait `From<<T as Trait>::Error>` is not implemented for `ApplicationError`
+   |           |
+   |           this can't be annotated with `?` because it has type `Result<_, <T as Trait>::Error>`
+   |
+note: `ApplicationError` needs to implement `From<<T as Trait>::Error>`
+  --> $DIR/suggest-complex-bound-on-method.rs:12:1
+   |
+LL | enum ApplicationError {
+   | ^^^^^^^^^^^^^^^^^^^^^
+   = note: the question mark operation (`?`) implicitly performs a conversion on the error value using the `From` trait
+help: consider introducing a `where` clause, but there might be an alternative better way to express this requirement
+   |
+LL |     fn thing<T: Trait>(&self, t: T) -> Result<(), ApplicationError> where ApplicationError: From<<T as Trait>::Error> {
+   |                                                                     +++++++++++++++++++++++++++++++++++++++++++++++++
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.