Bug 1945020 - build(rust): bump minimum Rust version 1.76 → 1.82 r=glandium

…but for ASAN/TSAN, use a hack: a 1.82.0 nightly commit that tolerates
`unsafe extern` blocks, but doesn't break our current toolchain patches.

Differential Revision: https://phabricator.services.mozilla.com/D236028

Cargo.toml

@@ -58,7 +58,7 @@ exclude = [
 resolver = "2"
 
 [workspace.package]
-rust-version = "1.76.0"
+rust-version = "1.82.0"
 
 [workspace.dependencies]
 # Shared across multiple UniFFI consumers.

build/build-rust/rust-vendor-std.patch

@@ -12,10 +12,10 @@ For firefox's purposes, these patches still work fine, and are necessary
 to make -Zbuild-std work in a vendored environment.
 
 diff --git a/src/bootstrap/src/core/build_steps/dist.rs b/src/bootstrap/src/core/build_steps/dist.rs
-index 012d64e5344..aedb53358ef 100644
+index 58f86aa996d..ef8c1584011 100644
 --- a/src/bootstrap/src/core/build_steps/dist.rs
 +++ b/src/bootstrap/src/core/build_steps/dist.rs
-@@ -927,6 +927,31 @@ fn run(self, builder: &Builder<'_>) -> GeneratedTarball {
+@@ -941,6 +941,35 @@ fn run(self, builder: &Builder<'_>) -> GeneratedTarball {
              builder.copy_link(&builder.src.join(file), &dst_src.join(file));
          }
  
@@ -40,7 +40,11 @@ index 012d64e5344..aedb53358ef 100644
 +        cmd.env("RUSTC_BOOTSTRAP", "1");
 +        builder.info("Dist src");
 +        let _time = timeit(builder);
-+        builder.run(&mut cmd);
++        builder.run(
++            &mut cmd,
++            crate::utils::exec::OutputMode::Print,
++            crate::utils::exec::OutputMode::Print,
++        );
 +
 +        builder.remove(&temp_lock);
 +
@@ -48,10 +52,10 @@ index 012d64e5344..aedb53358ef 100644
      }
  }
 diff --git a/src/bootstrap/src/lib.rs b/src/bootstrap/src/lib.rs
-index 5ed6b357e20..ad617948c4b 100644
+index 453fb39327d..af579af9eca 100644
 --- a/src/bootstrap/src/lib.rs
 +++ b/src/bootstrap/src/lib.rs
-@@ -1649,6 +1649,30 @@ fn read_stamp_file(&self, stamp: &Path) -> Vec<(PathBuf, DependencyType)> {
+@@ -1732,6 +1732,30 @@ fn read_stamp_file(&self, stamp: &Path) -> Vec<(PathBuf, DependencyType)> {
          paths
      }
  
@@ -65,7 +69,7 @@ index 5ed6b357e20..ad617948c4b 100644
 +        if src == dst {
 +            return;
 +        }
-+        let _ = fs::remove_file(&dst);
++        let _ = fs::remove_file(dst);
 +        let metadata = t!(src.symlink_metadata());
 +        if let Err(e) = fs::copy(src, dst) {
 +            panic!("failed to copy `{}` to `{}`: {}", src.display(), dst.display(), e)

docs/writing-rust-code/update-policy.md

@@ -164,7 +164,7 @@ Here are the Rust versions for each Firefox version.
 | Firefox 135 | Rust 1.83.0 | 1.76.0 | 2024 November 28 | 2025 January 2 | 2025 February 4
 | Firefox 136 | Rust 1.84.0 | 1.76.0 | 2025 January 9 | 2025 January 30 | 2025 March 4
 | **Estimated** |
-| Firefox 137 | Rust 1.85.0 | ? | 2025 February 20 | 2025 February 27 | 2025 April 1
+| Firefox 137 | Rust 1.85.0 | 1.83.0 | 2025 February 20 | 2025 February 27 | 2025 April 1
 | Firefox 138 | Rust 1.85.0 | ? | 2025 February 20 | 2025 March 27 | 2025 April 29
 | Firefox 139 | Rust 1.86.0 | ? | 2025 April 3 | 2025 April 24 | 2025 May 27
 | Firefox 140 | Rust 1.87.0 | ? | 2025 May 15 | 2025 May 22 | 2025 June 24

python/mozboot/mozboot/util.py

@@ -13,7 +13,7 @@ from mach.site import PythonVirtualenv
 from mach.util import get_state_dir
 
 # Keep in sync with rust-version in top-level Cargo.toml.
-MINIMUM_RUST_VERSION = "1.76.0"
+MINIMUM_RUST_VERSION = "1.82.0"
 
 
 def get_tools_dir(srcdir=False):

taskcluster/kinds/fetch/toolchains.yml

@@ -379,7 +379,10 @@ rust-1.81.0:
         type: git
         include-dot-git: true
         repo: https://github.com/rust-lang/rust/
-        revision: eeb90cda1969383f56a2637cbd3037bdf598841c
+        # NOTE: This is 1.81.0 and then some, to accommodate compiling some 1.82.0 code without
+        # breaking patches we use for sanitizers. See
+        # <https://bugzilla.mozilla.org/show_bug.cgi?id=1915537> for follow-up.
+        revision: ab1527f1d6560168f9fd36fa8cd7ba677c1d36ad
 
 rust-nightly:
     description: Rust nightly source code

taskcluster/kinds/toolchain/rust.yml

@@ -11,12 +11,12 @@ task-defaults:
         script: repack_rust.py
         toolchain-artifact: public/build/rustc.tar.zst
 
-linux64-rust-1.76:
+linux64-rust-1.82:
     treeherder:
-        symbol: TL(rust-1.76)
+        symbol: TL(rust-1.82)
     run:
         arguments: [
-            '--channel', '1.76.0',
+            '--channel', '1.82.0',
             '--host', 'x86_64-unknown-linux-gnu',
             '--target', 'x86_64-unknown-linux-gnu',
             '--target', 'i686-unknown-linux-gnu',