Backport PR #15429: Fix OSX build on azure

jklymak · MeeseeksDev[bot] · commit dedc7ff642a6 · 2019-10-28T00:54:39.000Z
diff --git a/ci/azure-pipelines-steps.yml b/ci/azure-pipelines-steps.yml
@@ -32,6 +32,7 @@ steps:
 
 - ${{ if eq(parameters.installer, 'brew') }}:
   - script: |
+      brew cask install xquartz
       brew install pkg-config ffmpeg imagemagick mplayer ccache
     displayName: 'Install dependencies with brew'
 
