How to kill VBCSCompiler.exe on Ubuntu agent? - msbuild

Question

I created an Azure Devops Build pipeline and i am trying to build my ASP.NET MVC and Angular hybrid site project on bitbucket (git).
The project first gets checked out, and nuget restores the necessary packages, and then the .NET builds. I used windows 2019 as azure pipeline agent for the build to succeed. however, Its taking about 7 minutes to complete, whilst running the tasks (besides .Net) on a ubuntu agent is much faster! takes around 2 mins instead!
Therefore, I'd like to use ubuntu, but im running into an issue with the MSBuild task...
"/home/vsts/work/1/s/Bobby.ProjectA/Bobby.ProjectA.csproj" (default target) (1) ->
(KillVBCSCompilerAndRetryCopy target) ->
/home/vsts/work/1/s/packages/Microsoft.CodeDom.Providers.DotNetCompilerPlatform.1.0.8/build/net45/Microsoft.CodeDom.Providers.DotNetCompilerPlatform.props(23,5):
error MSB4044: The "KillProcess" task was not given a value for the required parameter "ImagePath". [/home/vsts/work/1/s/Bobby.ProjectA/Bobby.ProjectA.csproj]
According to this post, VBCSCompiler.exe continues running from the Compiler Nuget package (nuget restore task?) so it locks the src folders and prevented future builds from running, e.g. causing error like this:
/home/vsts/work/1/s/packages/Microsoft.CodeDom.Providers.DotNetCompilerPlatform.1.0.8/build/net45/Microsoft.CodeDom.Providers.DotNetCompilerPlatform.props(17,5):
warning MSB3021: Unable to copy file "/home/vsts/work/1/s/packages/Microsoft.Net.Compilers.2.4.0/build/../tools/csc.exe" to "/bin/roslyn/csc.exe". Access to the path '/bin/roslyn' is denied. [/home/vsts/work/1/s/Bobby.ProjectA/Bobby.ProjectA.csproj]
So the solution would be to kill the VBCSCompiler.exe but since i cant actually access the hosted machine during the build, im not sure how to do that.
screenshot of my pipeline so far:
Am i facing a dead-end path here with this approach? The build runs fine on windows 2019 but it just takes too long, so thats why if i can make it run on ubuntu successfully that would be great!

Answer 1

You can have a try with below workarounds:
1,Set MSBUILD arguements /p:UseSharedCompilation=false.
You can add above arguement to the msbuild arguements field of the msbuild task. See here.
2,Upgrade Microsoft.CodeDom.Providers.DotNetCompilerPlatform nupkg to the latest and remove Microsoft.Net.Compilers nupkg from your project. See here for more information.
3, Try Specifing the TTL of Roslyn compiler server.
You can define a pipeline variable VBCSCOMPILER_TTL on the Variable tab to specify a shorter idle time for VBCSCompiler.exe
Or you can add <providerOption name="CompilerServerTimeToLive" value="[num of seconds]" /> under system.codedom/compilers/compiler in the config file. See here for more information.
4, Use CheckIfShouldKillVBCSCompiler target:
You can try add below to your csproj file:
<Target Name="CheckIfShouldKillVBCSCompiler">
<PropertyGroup>
<ShouldKillVBCSCompiler>true</ShouldKillVBCSCompiler>
</PropertyGroup>
</Target>
See here.

Answer 2

The build on Ubuntu 20 finally worked! I don't know why removing these lines resolved the VBCSCompiler issue, but by doing so, the msbuild completed successfully on Ubunutu 20 agent!!
Remove the following lines from the .csproj file:
<Import Project="..\packages\Microsoft.Net.Compilers.2.4.0\build\Microsoft.Net.Compilers.props" Condition="Exists('..\packages\Microsoft.Net.Compilers.2.4.0\build\Microsoft.Net.Compilers.props')" />
<Error Condition="!Exists('..\packages\Microsoft.Net.Compilers.2.4.0\build\Microsoft.Net.Compilers.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.Net.Compilers.2.4.0\build\Microsoft.Net.Compilers.props'))" />
<Error Condition="!Exists('..\packages\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.1.0.8\build\net45\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.props')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.1.0.8\build\net45\Microsoft.CodeDom.Providers.DotNetCompilerPlatform.props'))" />
To give some context to the answer, this post here indicated that converting from MSBuild-Integrated Package Restore to Automatic Package Restore (nuget restore task) implied that the Microsoft.Net.Compilers <Import> and <Error Condition> snippets are no longer relevant/needed in the .csproj file.