[gtk/wip/otte/macos-werror: 8/8] CI: turn on -Werror for MacOS build

[Benjamin Otte <otte src gnome org>]

commit 3c4ca29c4765c648a0a2b6ba9948290968e028bb
Author: Benjamin Otte <otte redhat com>
Date:   Wed Nov 3 23:35:03 2021 +0100

    CI: turn on -Werror for MacOS build
    
    The build is error-free and we want to keep it that way.
    
    We'd also like to make Timm do real work instead of having to fix clang
    warnings all the time and this build is a clang build.

 .gitlab-ci.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 990ac48add..6eb7393086 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -172,7 +172,8 @@ macos:
     - export PATH=/Users/gitlabrunner/Library/Python/3.7/bin:$PATH
     - export MESON_FORCE_BACKTRACE=1
   script:
-    - meson -Dx11-backend=false
+    - meson ${COMMON_MESON_FLAGS}
+            -Dx11-backend=false
             -Dbroadway-backend=true
             -Dmacos-backend=true
             -Dmedia-gstreamer=disabled