gitlab-ci: Bump Mesa to 25.2.2

Notably including
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35915
which is needed for some upcoming MRs.
Returning to a proper release also makes it easier to understand
what we are testing against.

Mesa 25.2 requires Meson >= 1.4 and libX11 >= 1.8. The later requires
autoconf >= 2.70.

Signed-off-by: Robert Mader <robert.mader@collabora.com>

.gitlab-ci.yml

@@ -43,7 +43,7 @@
 variables:
   FDO_UPSTREAM_REPO: wayland/weston
   FDO_REPO_SUFFIX: "$BUILD_OS-$FDO_DISTRIBUTION_VERSION/$BUILD_ARCH"
-  FDO_DISTRIBUTION_TAG: '2025-07-17-vulkan-headers'
+  FDO_DISTRIBUTION_TAG: '2025-09-04-mesa-25.2.2'
 
 
 include:

.gitlab-ci/build-deps.sh

@@ -28,7 +28,7 @@ esac
 # Build and install Meson. Generally we want to keep this in sync with what
 # we require inside meson.build.
 fdo_log_section_start_collapsed install_meson "install_meson"
-pip3 install $PIP_ARGS git+https://github.com/mesonbuild/meson.git@1.3.2
+pip3 install $PIP_ARGS git+https://github.com/mesonbuild/meson.git@1.4.2
 export PATH=$HOME/.local/bin:$PATH
 
 # Our docs are built using Sphinx (top-level organisation and final HTML/CSS
@@ -159,9 +159,30 @@ fdo_log_section_end install_vulkan_headers
 # please be prepared for some of the tests to change output, which will need to
 # be manually inspected for correctness.
 fdo_log_section_start_collapsed install_mesa "install_mesa"
-git clone --single-branch --branch main https://gitlab.freedesktop.org/mesa/mesa.git
+wget https://ftp.gnu.org/gnu/autoconf/autoconf-2.72.tar.xz
+tar -xJf autoconf-2.72.tar.xz
+cd autoconf-2.72
+./configure
+make
+make install
+cd ..
+rm -rf autoconf-2.72*
+
+# Mesa >= 25.2 depends on libX11 >= 1.8, which is not available in the Debian
+# LTS images.
+git clone --branch libX11-1.8.12 --depth=1 https://gitlab.freedesktop.org/xorg/lib/libx11.git
+cd libx11
+autoreconf -ivf
+mkdir _builddir
+cd _builddir
+../configure --disable-silent-rules --enable-specs
+make ${MAKEFLAGS}
+make install
+cd ../..
+rm -rf libx11
+
+git clone --branch mesa-25.2.2 --depth=1 https://gitlab.freedesktop.org/mesa/mesa.git
 cd mesa
-git checkout -b snapshot 7b68e1da91732b7d9bb9bf620cf8d4f63a48ea8c
 meson setup build --wrap-mode=nofallback -Dauto_features=disabled \
 	-Dgallium-drivers=llvmpipe -Dvulkan-drivers=swrast -Dvideo-codecs= \
 	-Degl=enabled -Dgbm=enabled -Dgles2=enabled -Dllvm=enabled \

.gitlab-ci/debian-install.sh

@@ -29,8 +29,12 @@ MESA_DEV_PKGS="
 # These get temporarily installed for other build dependencies and then
 # force-removed.
 # cmake is used by Vulkan-Headers
+# wget is used by autoconf
+# xutils-dev is used by libX11
 BUILD_DEV_PKGS="
 	cmake
+	wget
+	xutils-dev
 "
 
 # Needed for running the custom-built mesa