mesa: Bump required Rust version to 1.78

The Linux kernel requires Rust 1.78 since version 6.10. Thus, this update is
in line with our Rust update policy.

Reviewed-by: Karol Herbst <kherbst@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31510>

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

@@ -11,11 +11,8 @@ set -ex
 mkdir -p "$HOME"/.cargo
 ln -s /usr/local/bin "$HOME"/.cargo/bin
 
-# Rusticl requires at least Rust 1.66.0 and NAK requires 1.73.0
-#
-# Also, pick a specific snapshot from rustup so the compiler doesn't drift on
-# us.
-RUST_VERSION=1.76.0-2024-02-08
+# Pick a specific snapshot from rustup so the compiler doesn't drift on us.
+RUST_VERSION=1.78.0-2024-05-02
 
 # 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

.gitlab-ci/image-tags.yml

@@ -13,7 +13,7 @@
 
 variables:
    DEBIAN_X86_64_BUILD_BASE_IMAGE: "debian/x86_64_build-base"
-   DEBIAN_BASE_TAG: "20241106-wlproto2"
+   DEBIAN_BASE_TAG: "20241117-rustc-bump"
 
    DEBIAN_X86_64_BUILD_IMAGE_PATH: "debian/x86_64_build"
    DEBIAN_BUILD_TAG: "20241106-wlproto2"

docs/rusticl.rst

@@ -48,7 +48,7 @@ To build Rusticl you need to satisfy the following build dependencies:
 
 The minimum versions to build Rusticl are:
 
--  Rust: 1.76
+-  Rust: 1.78
 -  Meson: 1.4.0
 -  Bindgen: 0.65.0
 -  LLVM: 15.0.0

meson.build

@@ -784,8 +784,8 @@ if with_gallium_rusticl or with_nouveau_vk or with_tools.contains('etnaviv')
   rustc = meson.get_compiler('rust')
   rust = import('rust')
 
-  if rustc.version().version_compare('< 1.76')
-    error('Mesa requires Rust 1.76.0 or newer')
+  if rustc.version().version_compare('< 1.78')
+    error('Mesa requires Rust 1.78.0 or newer')
   endif
 
   bindgen_version = find_program('bindgen').version()