dotnet restore erroring on NuGet.Config being used by another process

[cataggar]

NuGet Product Used

dotnet.exe

Product Version

dotnet sdk 9.0.100

Worked before?

dotnet sdk 8.0.401

Impact

I'm unable to use this version

Repro Steps & Context

Here is the internal pull request to reproduce.

I am often getting this error even with --disable-parallel:

~/ms/avs/src/conveyor/conveyor> dotnet build --disable-parallel
C:\Program Files\dotnet\sdk\9.0.100\NuGet.targets(751,5): error :
Unexpected failure reading NuGet.Config. Path: 'C:\Users\cataggar\AppData\Roaming\NuGet\NuGet.Config'.
The process cannot access the file 'C:\Users\cataggar\AppData\Roaming\NuGet\NuGet.Config' because it is being used by another process.

Verbose Logs

No response

[nguerrera]

I am seeing this as well. It also seems to impact 8.0.404, but not 8.0.403.

It is not 100% reproducible for me, but happening often, and only recently.

[tmat]

Perhaps nuget should include list of processes that have the paths open in the exception message. See
dotnet/roslyn#75946
dotnet/runtime#109927

[nguerrera]

If I hit this again today, I will try to debug to provide more info.

[nguerrera]

I can't explain it, but this hasn't happened to me in the last few days while it was happening a lot before. Possibly something that was locking the files like VS got an update?

[jeffkl]

I am not aware of any changes in this area of the code in the 6.12 release. I wonder if its an anti-malware process that's locking the file?

[tmat]

@jeffkl Could you implement #13937 (comment)? Might help with diagnostics.

[jeffkl]

We can add it to our backlog for sure.