build: Compile schemas locally for use in build tests

So they don't need to be installed system-wide before build testing
can work.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/3368
Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3800>

data/meson.build

@@ -27,20 +27,33 @@ gschema_config.set('XWAYLAND_GRAB_DEFAULT_ACCESS_RULES',
                    xwayland_grab_default_access_rules)
 
 schemadir = datadir / 'glib-2.0' / 'schemas'
-configure_file(
+schema_xmls = []
+schema_xmls += configure_file(
   input: 'org.gnome.mutter.gschema.xml.in',
   output: 'org.gnome.mutter.gschema.xml',
   configuration: gschema_config,
   install_dir: schemadir
 )
 
-configure_file(
+schema_xmls += configure_file(
   input: 'org.gnome.mutter.wayland.gschema.xml.in',
   output: 'org.gnome.mutter.wayland.gschema.xml',
   configuration: gschema_config,
   install_dir: schemadir
 )
 
+locally_compiled_schemas_dir = meson.current_build_dir()
+
+locally_compiled_schemas = custom_target(
+  output: 'gschemas.compiled',
+  depend_files: schema_xmls,
+  command: ['glib-compile-schemas', locally_compiled_schemas_dir],
+)
+
+locally_compiled_schemas_dep = declare_dependency(
+  sources: locally_compiled_schemas
+)
+
 install_data(['mutter-schemas.convert'],
   install_dir: datadir / 'GConf/gsettings',
 )

src/tests/clutter/conform/meson.build

@@ -55,6 +55,7 @@ test_env.set('G_TEST_SRCDIR', meson.current_source_dir())
 test_env.set('G_TEST_BUILDDIR', meson.current_build_dir())
 test_env.set('G_ENABLE_DIAGNOSTIC', '0')
 test_env.set('CLUTTER_ENABLE_DIAGNOSTIC', '0')
+test_env.set('GSETTINGS_SCHEMA_DIR', locally_compiled_schemas_dir)
 
 foreach test : clutter_conform_tests
   test_executable = executable('@0@'.format(test),

src/tests/cogl/conform/meson.build

@@ -65,6 +65,7 @@ test_env = environment()
 test_env.set('G_TEST_SRCDIR', meson.current_source_dir())
 test_env.set('G_TEST_BUILDDIR', meson.current_build_dir())
 test_env.set('G_ENABLE_DIAGNOSTIC', '0')
+test_env.set('GSETTINGS_SCHEMA_DIR', locally_compiled_schemas_dir)
 
 cogl_test_variants = [ 'gl3', 'gles2' ]
 

src/tests/cogl/unit/meson.build

@@ -14,6 +14,7 @@ test_env = environment()
 test_env.set('G_TEST_SRCDIR', meson.current_source_dir())
 test_env.set('G_TEST_BUILDDIR', meson.current_build_dir())
 test_env.set('G_ENABLE_DIAGNOSTIC', '0')
+test_env.set('GSETTINGS_SCHEMA_DIR', locally_compiled_schemas_dir)
 
 foreach unit_test: cogl_unit_tests
   test_name = 'cogl-' + unit_test[0]

src/tests/meson.build

@@ -42,6 +42,7 @@ tests_deps = [
   libmutter_clutter_dep,
   libmutter_dep,
   mutter_deps,
+  locally_compiled_schemas_dep,
 ]
 
 libmutter_test = shared_library(libmutter_test_name,
@@ -144,7 +145,8 @@ test_env_variables = {
   'G_TEST_BUILDDIR': mutter_builddir,
   'XDG_CONFIG_HOME': mutter_builddir / '.config',
   'MUTTER_TEST_PLUGIN_PATH': '@0@'.format(default_plugin.full_path()),
-  'GSETTINGS_SCHEMA_DIR': mutter_builddir / 'src' / 'tests',
+  'GSETTINGS_SCHEMA_DIR': ':'.join([mutter_builddir / 'src' / 'tests',
+                                    locally_compiled_schemas_dir]),
 }
 
 foreach name, value: test_env_variables