dotnet build leaves running dotnet.exe processes after it finishes (.csproj specific)

Steps to reproduce

.csproj files attached buildleak.zip Enter c directory Open task manager/details view observe no dotnet.exe processes are running (clean test environment) run dotent build

Expected behavior

No dotnet.exe processes left

Actual behavior

dotnet.exe processes left

Environment data

dotnet --info output:

.NET Core SDK (reflecting any global.json): Version: 2.1.300 Commit: adab45bf0c

Runtime Environment: OS Name: Windows OS Version: 10.0.17134 OS Platform: Windows RID: win10-x64 Base Path: C:\Program Files\dotnet\sdk\2.1.300\

Host (useful for support): Version: 2.1.0 Commit: caa7b7e2ba

.NET Core SDKs installed: 1.0.0 [C:\Program Files\dotnet\sdk] 1.0.1 [C:\Program Files\dotnet\sdk] 1.0.4 [C:\Program Files\dotnet\sdk] 1.1.0 [C:\Program Files\dotnet\sdk] 2.0.0 [C:\Program Files\dotnet\sdk] 2.1.200 [C:\Program Files\dotnet\sdk] 2.1.300 [C:\Program Files\dotnet\sdk]

.NET Core runtimes installed: Microsoft.AspNetCore.All 2.1.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All] Microsoft.AspNetCore.App 2.1.0 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App] Microsoft.NETCore.App 1.0.4 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 1.0.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 1.1.1 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 1.1.2 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.0.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.0.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App] Microsoft.NETCore.App 2.1.0 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs: https://aka.ms/dotnet-download

[livarcocc]

This is by design in 2.1.300.

As part of our perf improvements, we introduced three persistent servers with the goal of reduce our JIT time. The servers are the razor compilation server, the vbcscompiler server and the msbuild node re-use server.

If you don’t want them staying around when you are done building, you can invoke dotnet build-server shutdown to turn them off.

If you don’t want them to start to begin with, you can set different properties/environment variables to prevent them from starting. From @peterhuene:

Use -p:UseRazorBuildServer=false to disable the Razor (rzc) server.

Use -p:UseSharedCompilation=false to disable the Roslyn (vbcscompiler) server.

For MSBuild, pass /nodeReuse:false on the command line to disable node re-use.

[jhudsoncedaron]

They’re causing spurious build failures due to holding locks.