MSBuild error MSB3073 "The batch file cannot be found"

[This was originally posted at http://timstall.dotnetdevelopersjournal.com/msbuild_error_msb3073_the_batch_file_cannot_be_found.htm]

We've migrated to MSTest, and are running tests through MSBuild. I came across an interesting issue (that seems like a bug).

Normally I would expect that if the test passes in Test Viewer (the UI), then it would also pass when I run it in MSTest from the command line, and it would still pass when I call it from MSBuild. However, I found this not always so.

One of my tests wrote out files to the temp directory, as generated by "System.IO.Path.GetTempPath()". I then cleaned up the test output by deleting the directory, and recreating it. This worked fine in both UI, and MSTest, but failed in MSBuild with the following error:

Run Configuration: Default Run Configuration
The batch file cannot be found.
C:\myProject\myBuild.msbuild(21,5): error MSB3073:

The command ""C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\MsTest"
/testcontainer:C:\myTests.dll /resultsfile:myOutput\UnitTests.trx" exited with code 1.
Done building target "UnitTest" in project "myBuild.msbuild" -- FAILED.

By appending a sub directory to the temp directory, like "System.IO.Path.GetTempPath()" + "temp\", the tests all passed again. My guess is that MSBuild sent something to this output directory that my cleanup method was inadvertently deleting.