On nixpkgs /tmp/.X11-unix is not compatible with Xvfb requirement and the
test fails.
--- a/meson.build
+++ b/meson.build
@@ -775,12 +775,6 @@ if get_option('enable-x11')
         env: test_env,
         is_parallel : false,
     )
-    test(
-        'x11comp',
-        executable('test-x11comp', 'test/x11comp.c', dependencies: x11_test_dep),
-        env: test_env,
-        is_parallel : false,
-    )
 endif
 if get_option('enable-xkbregistry')
     test(