(mono) install mono from brew

Author: arturcic

build/stages/common-steps.yml

@@ -7,11 +7,13 @@ steps:
     installationPath: $(Agent.ToolsDirectory)/dotnet
 - task: CmdLine@2
   condition: eq( variables['Agent.OS'], 'Darwin' )
-  displayName: 'Select Mono version'
+  displayName: 'Use mono'
   inputs:
     script: |
-      SYMLINK=5_18_1
-      MONOPREFIX=/Library/Frameworks/Mono.framework/Versions/$SYMLINK
+      brew install mono
+      brew link --overwrite mono
+      SYMLINK=6.0.0.313
+      MONOPREFIX=/usr/local/Cellar/mono/$SYMLINK
       echo "##vso[task.setvariable variable=DYLD_FALLBACK_LIBRARY_PATH;]$MONOPREFIX/lib:/lib:/usr/lib:$DYLD_LIBRARY_FALLBACK_PATH"
       echo "##vso[task.setvariable variable=PKG_CONFIG_PATH;]$MONOPREFIX/lib/pkgconfig:$MONOPREFIX/share/pkgconfig:$PKG_CONFIG_PATH"
       echo "##vso[task.setvariable variable=PATH;]$MONOPREFIX/bin:$PATH"

src/GitVersionExe/SpecifiedArgumentRunner.cs

@@ -23,7 +23,7 @@ private static string GetMsBuildToolPath()
             }
             if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
             {
-                return "/Library/Frameworks/Mono.framework/Versions/Current/Commands/msbuild";
+                return "/usr/local/bin/msbuild";
             }
             throw new Exception("MsBuild not found");
         }