dotnet publish failing because of unknown option

I am using the .NET Cli runner.  Here is what shows in the logs

dotnet.exe publish MyProject.API --framework net461 --configuration Release --output C:\BuildAgent\work\218e0226f52919e9\tempout --version-suffix 1.0.10852 @C:\BuildAgent\temp\agentTmp\1.rsp

The problem is that it does not know what to do with

@C:\BuildAgent\temp\agentTmp\1.rsp

I cant figure out where that is coming from.  I have not set anything up pointing to that directory