Exclude is overzealous when exclude pattern is an absolute path prefix of include directory

When building an SDK project, the source files are not being collected correctly, causing a “CS5001: Program does not contain a static ‘Main’ method suitable for an entry point” error. If I change the OutputPath to anything other than a substring of the source path, all source files are picked up just fine and build succeeds. Issue only happens after the 2nd build (presumably because the output folder is not empty).

Still repro’ed on latest stable 2.2, but could not repro on 3.0.100-preview-009812, so possibly an issue that only affects < 3.0.

Repro steps:

mkdir C:\Temp2 && cd C:\Temp2
@echo {"sdk":{"version":"2.2.100"}}> global.json
mkdir TestFullPath && cd TestFullPath && dotnet new console && cd ..
dotnet build C:\Temp2\TestFullPath\TestFullPath.csproj -o C:\Temp2\Test
dotnet build C:\Temp2\TestFullPath\TestFullPath.csproj -o C:\Temp2\Test

Output:

C:\Temp2
λ cd ..

C:\
λ rm -rf C:\Temp2

C:\
λ mkdir C:\Temp2 && cd C:\Temp2

C:\Temp2
λ @echo {"sdk":{"version":"2.2.100"}}> global.json

C:\Temp2
λ mkdir TestFullPath && cd TestFullPath && dotnet new console && cd ..
The template "Console Application" was created successfully.

Processing post-creation actions...
Running 'dotnet restore' on C:\Temp2\TestFullPath\TestFullPath.csproj...
  Restoring packages for C:\Temp2\TestFullPath\TestFullPath.csproj...
  Generating MSBuild file C:\Temp2\TestFullPath\obj\TestFullPath.csproj.nuget.g.props.
  Generating MSBuild file C:\Temp2\TestFullPath\obj\TestFullPath.csproj.nuget.g.targets.
  Restore completed in 193.24 ms for C:\Temp2\TestFullPath\TestFullPath.csproj.

Restore succeeded.


C:\Temp2
λ dotnet build C:\Temp2\TestFullPath\TestFullPath.csproj -o C:\Temp2\Test
Microsoft (R) Build Engine version 15.9.20+g88f5fadfbe for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Restore completed in 35.26 ms for C:\Temp2\TestFullPath\TestFullPath.csproj.
  TestFullPath -> C:\Temp2\Test\TestFullPath.dll

Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:00:01.06

C:\Temp2
λ dotnet build C:\Temp2\TestFullPath\TestFullPath.csproj -o C:\Temp2\Test
Microsoft (R) Build Engine version 15.9.20+g88f5fadfbe for .NET Core
Copyright (C) Microsoft Corporation. All rights reserved.

  Restore completed in 37.45 ms for C:\Temp2\TestFullPath\TestFullPath.csproj.
CSC : error CS5001: Program does not contain a static 'Main' method suitable for an entry point [C:\Temp2\TestFullPath\TestFullPath.csproj]

Build FAILED.

CSC : error CS5001: Program does not contain a static 'Main' method suitable for an entry point [C:\Temp2\TestFullPath\TestFullPath.csproj]
    0 Warning(s)
    1 Error(s)

Time Elapsed 00:00:00.94

[livarcocc]

Man, github is a small world, I actually went to school with @rla4, whether she remembers or not.

I am not sure exactly which change happened in 3.0 to fix this issue there. @peterhuene can you take a look? Depending on the change, we can try to do bar check and bring it the fix to 2.2 in a servicing release.

[rainersigwald]

Great find! Moved to Microsoft/msbuild#4175, with an even smaller repro. I understand the fix, too.