Tracking issue for release notes of #140525: Use lld by default on `x86_64-unknown-linux-gnu` stable

[rustbot]

This issue tracks the release notes text for #140525.

cc @lqd, @petrochenkov -- original issue/PR authors and assignees for drafting text

See the forge.rust-lang.org chapter about release notes for an overview of how the release team makes use of these tracking issues.

Release notes text

This section should be edited to specify the correct category(s) for the change, with succinct description(s) of what changed. Some things worth considering:

• Does this need an additional compat notes section?
• Was this a libs stabilization that should have additional headers to list new APIs under Stabilized APIs and Const Stabilized APIs?

# Compiler
- [Use `lld` by default on `x86_64-unknown-linux-gnu`](https://github.com/rust-lang/rust/pull/140525).

Tip

Use the previous releases for inspiration on how to write the release notes text and which categories to pick.

Release blog section

If this change is notable enough for inclusion in the blog post then this section should be edited to contain a draft for the blog post. Otherwise leave it empty.

# LLD is now used as the default linker on x86_64-unknown-linux-gnu

The `x86_64-unknown-linux-gnu` target will now use the LLD linker for linking Rust crates by default. This should result in much better linking performance vs the default GNU ld/BFD Linux linker, particularly for large programs, programs with a lot of debug information, and for incremental rebuilds.

In the vast majority of cases, LLD should be backwards compatible with GNU ld/BFD. However, if you do run into any new linker issues after this switch, you can always opt out using the `-C linker-features=-lld` compiler flag. Either by adding it to the usual `RUSTFLAGS` environment variable, or to a project's [`.cargo/config.toml`](https://doc.rust-lang.org/cargo/reference/config.html) configuration file,
like so:

```toml
[target.x86_64-unknown-linux-gnu]
rustflags = ["-Clinker-features=-lld"]
```

You can read more about the switch to LLD, some benchmark numbers and the opt out mechanism [here](https://blog.rust-lang.org/2025/09/01/rust-lld-on-1.90.0-stable/).

Note

If a blog post section is required the release-blog-post label should be added (@rustbot label +release-blog-post) to this issue as otherwise it may be missed by the release team.