[mutter/gbsneto/better-ci] ci: Install to Mutter and GNOME Shell to /usr

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 7a0b2f85a772eeabb3b31f4aac2922190190b68a
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Tue Apr 23 12:33:43 2019 -0300

    ci: Install to Mutter and GNOME Shell to /usr
    
    So GNOME Shell can find the pkg-config files properly.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/548

 .gitlab-ci.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 7b63bc1a6..62d15d9cc 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -16,7 +16,7 @@ build-mutter:
   stage: build
   script:
     - meson . build -Dbuildtype=debugoptimized -Degl_device=true -Dwayland_eglstream=true --werror
-    - ninja -C build
+    - ninja -C build --prefix /usr
     - ninja -C build install
   artifacts:
     expire_in: 1 day
@@ -52,7 +52,7 @@ can-build-gnome-shell:
     - meson install --no-rebuild -C build
   script:
     - .gitlab-ci/checkout-gnome-shell.sh
-    - meson gnome-shell gnome-shell/build
+    - meson gnome-shell gnome-shell/build --prefix /usr
     - ninja -C gnome-shell/build install
   only:
     - merge_requests