ci: use MSRV for build-for-tests jobs and recent version in build-only jobs and CI components

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37414>

.gitlab-ci/container/alpine/x86_64_build.sh

@@ -66,7 +66,7 @@ pip3 install --break-system-packages sphinx===8.2.3 hawkmoth===0.19.0
 
 . .gitlab-ci/container/install-meson.sh
 
-. .gitlab-ci/container/build-rust.sh
+. .gitlab-ci/container/build-rust.sh build
 
 EXTRA_MESON_ARGS='--prefix=/usr' \
 . .gitlab-ci/container/build-wayland.sh

.gitlab-ci/container/build-rust.sh

@@ -14,15 +14,21 @@ section_start rust "Building Rust toolchain"
 
 # This version number should match what we require in meson.build so we catch
 # build issues from patches relying on new features in newer Rust versions.
-# If we need to bump this, we should also bump the version in meson.build.
+# Keep this is sync with the `rustc.version()` check in meson.build, and with
-RUST_VERSION=1.82.0
+# the `rustup default` line in .gitlab-ci/meson/build.sh
+MINIMUM_SUPPORTED_RUST_VERSION=1.82.0
+
+# This version number can be bumped freely, to benefit from the latest
+# diagnostics in CI `build-only` jobs, and for building external CI
+# components.
+LATEST_RUST_VERSION=1.90.0
 
 # For rust in Mesa, we use rustup to install.  This lets us pick an arbitrary
 # version of the compiler, rather than whatever the container's Debian comes
 # with.
 curl -L --retry 4 -f --retry-all-errors --retry-delay 60 \
     --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- \
-      --default-toolchain $RUST_VERSION \
+      --default-toolchain $LATEST_RUST_VERSION \
       --profile minimal \
       --component clippy,rustfmt \
       -y
@@ -31,6 +37,11 @@ curl -L --retry 4 -f --retry-all-errors --retry-delay 60 \
 # shellcheck disable=SC1091
 . "$HOME/.cargo/env"
 
+if [ "$1" = "build" ]
+then
+  rustup toolchain install --profile minimal --component clippy,rustfmt $MINIMUM_SUPPORTED_RUST_VERSION
+fi
+
 # Set up a config script for cross compiling -- cargo needs your system cc for
 # linking in cross builds, but doesn't know what you want to use for system cc.
 cat > "$HOME/.cargo/config" <<EOF

.gitlab-ci/container/debian/arm64_build.sh

@@ -115,7 +115,7 @@ arch=armhf
 
 . .gitlab-ci/container/build-libclc.sh
 
-. .gitlab-ci/container/build-rust.sh
+. .gitlab-ci/container/build-rust.sh build
 
 . .gitlab-ci/container/build-bindgen.sh
 

.gitlab-ci/container/debian/test-base.sh

@@ -223,7 +223,7 @@ section_end debian_setup
 
 ############### Install Rust toolchain
 
-. .gitlab-ci/container/build-rust.sh
+. .gitlab-ci/container/build-rust.sh test
 
 ############### Build Crosvm
 

.gitlab-ci/container/debian/x86_64_build-base.sh

@@ -103,7 +103,7 @@ pip3 install --break-system-packages "ci-fairy[s3] @ git+https://gitlab.freedesk
 
 . .gitlab-ci/container/install-meson.sh
 
-. .gitlab-ci/container/build-rust.sh
+. .gitlab-ci/container/build-rust.sh build
 
 ############### Uninstall ephemeral packages
 

.gitlab-ci/container/debian/x86_64_test-android.sh

@@ -84,7 +84,7 @@ DEBIAN_ARCH=amd64 \
 
 export ANDROID_NDK_HOME=/$ndk
 export RUST_TARGET=x86_64-linux-android
-. .gitlab-ci/container/build-rust.sh
+. .gitlab-ci/container/build-rust.sh test
 . .gitlab-ci/container/build-deqp-runner.sh
 
 # Properly uninstall rustup including cargo and init scripts on shells

.gitlab-ci/container/fedora/x86_64_build.sh

@@ -103,7 +103,7 @@ rm -rf $XORGMACROS_VERSION
 
 . .gitlab-ci/container/install-meson.sh
 
-. .gitlab-ci/container/build-rust.sh
+. .gitlab-ci/container/build-rust.sh build
 
 . .gitlab-ci/container/build-bindgen.sh
 

.gitlab-ci/image-tags.yml

@@ -19,11 +19,11 @@ include:
   - .gitlab-ci/conditional-build-image-tags.yml
 
 variables:
-  DEBIAN_BUILD_BASE_TAG: "20250901-trixie"
+  DEBIAN_BUILD_BASE_TAG: "20250917-two-rust"
-  DEBIAN_BUILD_TAG: "20250825-finds3"
+  DEBIAN_BUILD_TAG: "20250917-two-rust"
 
   DEBIAN_TEST_BASE_TAG: "20250901-trixie2"
-  DEBIAN_TEST_ANDROID_TAG: "20250911-angle"
+  DEBIAN_TEST_ANDROID_TAG: "20250917-two-rust"
   DEBIAN_TEST_GL_TAG: "20250911-piglit"
   DEBIAN_TEST_VIDEO_TAG: "20250813-vector"
   DEBIAN_TEST_VK_TAG: "20250911-piglit"

.gitlab-ci/meson/build.sh

@@ -41,6 +41,13 @@ if test -n "$LLVM_VERSION"; then
     $LLVM_CONFIG --version
 fi
 
+# Android manages the rust toolchain differently, ignore that case
+if [ "$CI_JOB_STAGE" = "build-for-tests" ] && [[ "$CI_JOB_NAME" != *android* ]]; then
+  # Keep this in sync with the `rustc.version()` check in meson.build, and
+  # MINIMUM_SUPPORTED_RUST_VERSION in .gitlab-ci/container/build-rust.sh
+  rustup default 1.82.0
+fi
+
 # cross-xfail-$CROSS, if it exists, contains a list of tests that are expected
 # to fail for the $CROSS configuration, one per line. you can then mark those
 # tests in their meson.build with:

meson.build

@@ -760,6 +760,9 @@ if with_gallium_rusticl or with_nouveau_vk or with_tools.contains('etnaviv') or
   rustc = meson.get_compiler('rust')
   rust = import('rust')
 
+  # Keep this in sync with the MINIMUM_SUPPORTED_RUST_VERSION in
+  # .gitlab-ci/container/build-rust.sh and the `rustup default` line in
+  # .gitlab-ci/meson/build.sh
   if rustc.version().version_compare('< 1.82')
     error('Mesa requires Rust 1.82.0 or newer')
   endif