5 files changed, 46 insertions, 16 deletions
diff --git a/src/bootstrap/bootstrap.py b/src/bootstrap/bootstrap.py
index f44a05a6b28..9dbc87c337c 100644
--- a/src/bootstrap/bootstrap.py
+++ b/src/bootstrap/bootstrap.py
@@ -623,7 +623,7 @@ class RustBuild(object):
 
     def should_fix_bins_and_dylibs(self):
         """Whether or not `fix_bin_or_dylib` needs to be run; can only be True
-        on NixOS.
+        on NixOS or if config.toml has `build.patch-binaries-for-nix` set.
         """
         if self._should_fix_bins_and_dylibs is not None:
             return self._should_fix_bins_and_dylibs
@@ -643,23 +643,31 @@ class RustBuild(object):
             if ostype != "Linux":
                 return False
 
-            # If the user has asked binaries to be patched for Nix, then
-            # don't check for NixOS or `/lib`.
+            # If the user has explicitly indicated whether binaries should be
+            # patched for Nix, then don't check for NixOS.
             if self.get_toml("patch-binaries-for-nix", "build") == "true":
                 return True
+            if self.get_toml("patch-binaries-for-nix", "build") == "false":
+                return False
 
             # Use `/etc/os-release` instead of `/etc/NIXOS`.
             # The latter one does not exist on NixOS when using tmpfs as root.
             try:
                 with open("/etc/os-release", "r") as f:
-                    if not any(ln.strip() in ("ID=nixos", "ID='nixos'", 'ID="nixos"') for ln in f):
-                        return False
+                    is_nixos = any(ln.strip() in ("ID=nixos", "ID='nixos'", 'ID="nixos"')
+                                   for ln in f)
             except FileNotFoundError:
-                return False
-            if os.path.exists("/lib"):
-                return False
+                is_nixos = False
 
-            return True
+            # If not on NixOS, then warn if user seems to be atop Nix shell
+            if not is_nixos:
+                in_nix_shell = os.getenv('IN_NIX_SHELL')
+                if in_nix_shell:
+                    print("The IN_NIX_SHELL environment variable is `{}`;".format(in_nix_shell),
+                          "you may need to set `patch-binaries-for-nix=true` in config.toml",
+                          file=sys.stderr)
+
+            return is_nixos
 
         answer = self._should_fix_bins_and_dylibs = get_answer()
         if answer:
diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
index 4821d20a898..e5fdac3ceda 100644
--- a/src/bootstrap/config.rs
+++ b/src/bootstrap/config.rs
@@ -137,7 +137,7 @@ pub struct Config {
     pub json_output: bool,
     pub test_compare_mode: bool,
     pub color: Color,
-    pub patch_binaries_for_nix: bool,
+    pub patch_binaries_for_nix: Option<bool>,
     pub stage0_metadata: Stage0Metadata,
 
     pub stdout_is_tty: bool,
@@ -1276,7 +1276,8 @@ impl Config {
         }
 
         config.initial_rustc = if let Some(rustc) = build.rustc {
-            config.check_build_rustc_version(&rustc);
+            // FIXME(#115065): re-enable this check
+            // config.check_build_rustc_version(&rustc);
             PathBuf::from(rustc)
         } else {
             config.download_beta_toolchain();
@@ -1338,7 +1339,7 @@ impl Config {
         set(&mut config.local_rebuild, build.local_rebuild);
         set(&mut config.print_step_timings, build.print_step_timings);
         set(&mut config.print_step_rusage, build.print_step_rusage);
-        set(&mut config.patch_binaries_for_nix, build.patch_binaries_for_nix);
+        config.patch_binaries_for_nix = build.patch_binaries_for_nix;
 
         config.verbose = cmp::max(config.verbose, flags.verbose as usize);
 
diff --git a/src/bootstrap/download.rs b/src/bootstrap/download.rs
index a4135b06e9d..17c308e915b 100644
--- a/src/bootstrap/download.rs
+++ b/src/bootstrap/download.rs
@@ -91,8 +91,8 @@ impl Config {
             // NOTE: this intentionally comes after the Linux check:
             // - patchelf only works with ELF files, so no need to run it on Mac or Windows
             // - On other Unix systems, there is no stable syscall interface, so Nix doesn't manage the global libc.
-            if self.patch_binaries_for_nix {
-                return true;
+            if let Some(explicit_value) = self.patch_binaries_for_nix {
+                return explicit_value;
             }
 
             // Use `/etc/os-release` instead of `/etc/NIXOS`.
@@ -105,7 +105,16 @@ impl Config {
                     matches!(l.trim(), "ID=nixos" | "ID='nixos'" | "ID=\"nixos\"")
                 }),
             };
-            is_nixos && !Path::new("/lib").exists()
+            if !is_nixos {
+                let in_nix_shell = env::var("IN_NIX_SHELL");
+                if let Ok(in_nix_shell) = in_nix_shell {
+                    eprintln!(
+                        "The IN_NIX_SHELL environment variable is `{in_nix_shell}`; \
+                         you may need to set `patch-binaries-for-nix=true` in config.toml"
+                    );
+                }
+            }
+            is_nixos
         });
         if val {
             eprintln!("info: You seem to be using Nix.");
diff --git a/src/bootstrap/test.rs b/src/bootstrap/test.rs
index d0d62db0807..d1018978f78 100644
--- a/src/bootstrap/test.rs
+++ b/src/bootstrap/test.rs
@@ -630,6 +630,10 @@ impl Step for Miri {
         cargo.env("MIRI_SYSROOT", &miri_sysroot);
         cargo.env("MIRI_HOST_SYSROOT", sysroot);
         cargo.env("MIRI", &miri);
+        if builder.config.locked_deps {
+            // enforce lockfiles
+            cargo.env("CARGO_EXTRA_FLAGS", "--locked");
+        }
 
         // Set the target.
         cargo.env("MIRI_TEST_TARGET", target.rustc_target_arg());
@@ -675,6 +679,9 @@ impl Step for Miri {
         );
         cargo.add_rustc_lib_path(builder, compiler);
         cargo.arg("--").arg("miri").arg("test");
+        if builder.config.locked_deps {
+            cargo.arg("--locked");
+        }
         cargo
             .arg("--manifest-path")
             .arg(builder.src.join("src/tools/miri/test-cargo-miri/Cargo.toml"));
@@ -1167,6 +1174,11 @@ impl Step for ExpandYamlAnchors {
     /// appropriate configuration for all our CI providers. This step ensures the tool was called
     /// by the user before committing CI changes.
     fn run(self, builder: &Builder<'_>) {
+        // Note: `.github/` is not included in dist-src tarballs
+        if !builder.src.join(".github/workflows/ci.yml").exists() {
+            builder.info("Skipping YAML anchors check: GitHub Actions config not found");
+            return;
+        }
         builder.info("Ensuring the YAML anchors in the GitHub Actions config were expanded");
         builder.run_delaying_failure(
             &mut builder.tool_cmd(Tool::ExpandYamlAnchors).arg("check").arg(&builder.src),
diff --git a/src/bootstrap/tool.rs b/src/bootstrap/tool.rs
index e6d27757ac6..07ff3da6b4a 100644
--- a/src/bootstrap/tool.rs
+++ b/src/bootstrap/tool.rs
@@ -601,7 +601,7 @@ pub struct RustAnalyzer {
 }
 
 impl RustAnalyzer {
-    pub const ALLOW_FEATURES: &str =
+    pub const ALLOW_FEATURES: &'static str =
         "proc_macro_internals,proc_macro_diagnostic,proc_macro_span,proc_macro_span_shrink";
 }