GenerateScopedCss: CompileSass task hangs if 50 or more SCSS files have to get compiled

[adiessl]

Describe the bug

If AspNetCore.SassCompiler is used in a project that has at least 50 SCSS files that have to be compiled it cannot be built.

To Reproduce

Steps to reproduce the behavior

Checkout the following repository: https://github.com/adiessl/SassCompilerTest

dotnet build .\BlazorApp\BlazorApp.csproj --> 50 of 250 SCSS files get compiled, then it hangs

Attempting to stop the build via Ctrl + C does not work, gives the following output:

Attempting to cancel the build...
C:\Users\{UserName}\.nuget\packages\aspnetcore.sasscompiler\1.51.0\build\AspNetCore.SassCompiler.targets(7,5): warning MSB4220: Waiting for the currently executing task "CompileSass" to cancel. [C:\{PathToRepo}\SassCompilerTest\BlazorApp\BlazorApp.csproj]

Killing the process dart.exe via Task Manager makes the build fail eventually.

dotnet build .\BlazorApp\BlazorApp.csproj --> another 50 SCSS files get compiled, then it hangs again.

Stopping the build has to be done the same way than above.

---

Remarks

1. Via Process Explorer one can find out that dart.exe is called as follows:

   "C:\Users\{UserName}\.nuget\packages\aspnetcore.sasscompiler\1.51.0\build\..\runtimes\win-x64\src\dart.exe" "C:\Users\{UserName}\.nuget\packages\aspnetcore.sasscompiler\1.51.0\build\..\runtimes\win-x64\src\sass.snapshot" --style=expanded --no-source-map --no-error-css --stop-on-error --no-unicode Components --update
   

   Executing this command directly via PowerShell for example compiles all 250 SCSS files without a problem.

2. Deleting 201 components with their SCSS files makes the build succeed. That means ...

   • ... 49 components: build succeeds.
   • ... 50 components: build hangs

Expected behavior

The compilation should work and the build should continue.

System info

dotnet --info

.NET SDK (reflecting any global.json):
 Version:   6.0.202
 Commit:    f8a55617d2

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.19044
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\Program Files\dotnet\sdk\6.0.202\

Host (useful for support):
  Version: 6.0.4
  Commit:  be98e88c76

[adiessl]

I debugged it and found the solution, see PR #72.