dotnet watch test --project <project>: gives MSBUILD : error MSB1001: Unknown switch

[FlukeFan]

Describe the bug

using dotnet watch test --project <project> gives the error:

MSBUILD : error MSB1001: Unknown switch.

To Reproduce

> dotnet new nunit --name UnitTests
> dotnet watch test --project UnitTests

gives:

MSBUILD : error MSB1001: Unknown switch.
    Full command line: 'C:\Program Files\dotnet\sdk\9.0.101\MSBuild.dll -maxcpucount -verbosity:m -tlp:default=auto -nologo -restore --property:VsTestUseMSBuildOutput=true -target:VSTest -nologo --project UnitTests -property:VSTestArtifactsProcessingMode=collect -property:VSTestSessionCorrelationId=5260_ac4d8286-281f-4973-bb3c-86e51e6ef8da -distributedlogger:Microsoft.DotNet.Tools.MSBuild.MSBuildLogger,C:\Program Files\dotnet\sdk\9.0.101\dotnet.dll*Microsoft.DotNet.Tools.MSBuild.MSBuildForwardingLogger,C:\Program Files\dotnet\sdk\9.0.101\dotnet.dll'
  Switches appended by response files:
Switch: --project

Further technical details

dotnet --version
9.0.101