Why MSBuildServer_Tests.CanShutdownServerProcess fails when NodeProviderInProc._nodeContexts capacity is set? #12187
Description
Context
This came up while implementing multi-threaded MSBuild feature, specifically allowing NodeProviderInProc to spawn multiple nodes instead of just one. When initializing the dictionary for the nodes, it makes sense to set capacity equal to BuildParameters.MaxNodeCountto improve performance, but that made this test fail Microsoft.Build.Engine.UnitTests.MSBuildServer_Tests.CanShutdownServerProcess(byBuildManager: True)
with call stack trace:
at Microsoft.Build.BackEnd.NodeManager.InitializeComponent(IBuildComponentHost host) in /_/src/Build/BackEnd/Components/Communications/NodeManager.cs:line 175
at Microsoft.Build.BackEnd.BuildComponentFactoryCollection.BuildComponentEntry.GetInstance(IBuildComponentHost host) in /_/src/Build/BackEnd/Components/BuildComponentFactoryCollection.cs:line 229
at Microsoft.Build.BackEnd.BuildComponentFactoryCollection.GetComponent(BuildComponentType type) in /_/src/Build/BackEnd/Components/BuildComponentFactoryCollection.cs:line 166
at Microsoft.Build.Execution.BuildManager.Microsoft.Build.BackEnd.IBuildComponentHost.GetComponent(BuildComponentType type) in /_/src/Build/BackEnd/BuildManager/BuildManager.cs:line 1289
at Microsoft.Build.Execution.BuildManager.ShutdownAllNodes() in /_/src/Build/BackEnd/BuildManager/BuildManager.cs:line 1237
at Microsoft.Build.Engine.UnitTests.MSBuildServer_Tests.CanShutdownServerProcess(Boolean byBuildManager) in /Users/runner/work/1/s/src/MSBuild.UnitTests/MSBuildServer_Tests.cs:line 254
Read more about it here
We should be able to set cpacity here
and investigate why the test fails.