From 5a8a8e0f2744d3ba3c1b411c02347e2c78c9a360 Mon Sep 17 00:00:00 2001
From: dybucc <149513579+dybucc@users.noreply.github.com>
Date: Sun, 31 May 2026 08:36:56 +0200
Subject: [PATCH] build: add `rust-toolchain.toml` file

Previously, one would have to manually set an override in `rustup` for
the `libc` repo if they weren't already using `nightly` as their default
toolchain channel. This meant stuff that relies on unstable features
like our `.rustfmt.toml` config would not work in those cases.

Adding a `rust-toolchain.toml` should fix this by either automatically
switching users to the `nightly` channel, or triggering a `rustup
install` if their installation does not yet include it.
---
 .github/workflows/ci.yaml | 2 +-
 ci/install-rust.sh        | 1 +
 rust-toolchain.toml       | 2 ++
 3 files changed, 4 insertions(+), 1 deletion(-)
 create mode 100644 rust-toolchain.toml

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index b38b889ac09ea..be783542c8386 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -55,7 +55,7 @@ jobs:
       # Here we use the latest stable Rust toolchain already installed by GitHub
       # Ideally we should run it for every target, but we cannot rely on unstable toolchains
       # due to Clippy not being consistent between them.
-      - run: cargo clippy --workspace --exclude libc-test --exclude ctest-test --all-targets -- -D warnings
+      - run: cargo +stable clippy --workspace --exclude libc-test --exclude ctest-test --all-targets -- -D warnings
 
   # This runs `cargo build --target ...` for all T1 and T2 targets`
   verify_build:
diff --git a/ci/install-rust.sh b/ci/install-rust.sh
index b40f1df4e7a54..f30446b9a397e 100755
--- a/ci/install-rust.sh
+++ b/ci/install-rust.sh
@@ -26,6 +26,7 @@ fi
 rustup set profile minimal
 rustup update --force "$toolchain" --no-self-update
 rustup default "$toolchain"
+rustup override set "$toolchain"
 
 if [ -n "${TARGET:-}" ]; then
     echo "Install target"
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
new file mode 100644
index 0000000000000..5d56faf9ae08c
--- /dev/null
+++ b/rust-toolchain.toml
@@ -0,0 +1,2 @@
+[toolchain]
+channel = "nightly"