ci: Build and publish system extensions

.gitlab-ci.yml

@@ -1,5 +1,6 @@
 include:
   - remote: 'https://gitlab.gnome.org/GNOME/citemplates/raw/HEAD/flatpak/flatpak_ci_initiative.yml'
+  - remote: 'https://gitlab.gnome.org/tchx84/citemplates/raw/sysext/sysext/sysext_ci_initiative.yml'
   - remote: 'https://gitlab.freedesktop.org/freedesktop/ci-templates/-/raw/057b052e682d8e5a20c1eb2dd60d5b87d2b56856/templates/fedora.yml'
   - remote: 'https://gitlab.freedesktop.org/freedesktop/ci-templates/-/raw/bc70242ffb8402243e934659ecc1a2d1c89eca2b/templates/ci-fairy.yml'
   - project: 'Infrastructure/openshift-images/gnome-release-service'
@@ -250,6 +251,18 @@ test-coverity:
     paths:
       - coverity
 
+sysext:
+  stage: build
+  variables:
+    SYSEXT_MESON_OPTIONS:
+      --werror
+      --fatal-meson-warnings
+      -Dextensions_app=false
+      -Dextensions-tool:bash_completion=disabled
+  before_script:
+    - .gitlab-ci/install-sysext-dependencies.sh
+  extends: .sysext.meson-build
+
 flatpak:
   stage: build
   needs: ["check_commit_log"]

.gitlab-ci/install-sysext-dependencies.sh

@@ -0,0 +1,34 @@
+#!/bin/bash
+#
+# This script ensures that all dependencies required to build and run
+# a GNOME Shell system extension are present in:
+#
+# The building environment, by installing these dependencies to the container.
+# The running environment, by bundling these dependencies with the extension.
+#
+
+set -e
+
+# Install dependencies to $SYSEXT_DEST_DIR to bundle these with the extension.
+
+if [ -z ${SYSEXT_DEST_DIR+x} ]; then
+  echo "SYSEXT_DEST_DIR is not defined"
+  exit 1
+fi
+
+# Ensure that we're building against (and bundling) the right mutter branch
+# and its dependencies:
+
+SCRIPT_DIR="$(dirname $0)"
+
+$SCRIPT_DIR/checkout-mutter.sh
+./mutter/.gitlab-ci/install-sysext-dependencies.sh
+
+meson setup mutter/build mutter --prefix=/usr --libdir="lib/$(gcc -print-multiarch)"
+meson compile -C mutter/build
+meson install -C mutter/build --destdir $SYSEXT_DEST_DIR
+
+sudo meson install -C mutter/build
+
+# Ensure that any other dependency missing in GNOME OS is installed and bundled
+# here as it was done with mutter: