GitVersion fails to pull a dymanic repository when on TeamCity

[RichiCoder1]

Here's the error message:

C:\Source\core [release/2.2.0 +1 ~4 -0 !]> .\tools\GitVersion.CommandLine\tools\GitVersion.exe /url "******" /u ******* /p ********* /b "refs/heads/release/2.2.0" /c ea0f3605343b5703b98815e8f34c04dda91f9564 /output json
INFO [08/25/15 16:14:47:55] Working directory: C:\Source\core
INFO [08/25/15 16:14:47:56] Applicable build agent found: 'TeamCity'.
ERROR [08/25/15 16:14:47:56] An unexpected error occurred:
System.Exception: Dynamic Git repositories must have a target branch (/b)
   at GitVersion.GitPreparer.CreateDynamicRepository(String targetPath, Authentication authentication, String repositoryUrl, String targetBranch, Boolean noFetch)
   at GitVersion.GitPreparer.Initialise(Boolean normaliseGitDirectory, String currentBranch)
   at GitVersion.ExecuteCore.ExecuteGitVersion(IFileSystem fileSystem, String targetUrl, String dynamicRepositoryLocation, Authentication authentication, String targetBranch, Boolean noFetch, String workingDirectory, String commitId)
   at GitVersion.SpecifiedArgumentRunner.Run(Arguments arguments, IFileSystem fileSystem)
   at GitVersion.Program.VerifyArgumentsAndRun()

Source at fault: https://github.com/GitTools/GitVersion/blob/master/src/GitVersionCore/ExecuteCore.cs#L20

TeamCity returns string.Empty which cases currentBranch ?? targetBranch to evaluate to string.Empty. Can be fixed by instead writing:

gitPreparer.Initialise(buildServer != null, string.IsNullOrWhiteSpace(currentBranch) ? targetBranch : currentBranch); 

This is a somewhat critical bug as it does block using 3.1.0 at all, though we're experimenting with a work around where we kill $env.TEAMCITY_VERSION for the lifetime of the git version run.

EDIT: Workaround worked :). World not as ending.

[furrot]

Any chance you'll publish the build soon for this? Can't figure out a workaround.

[JakeGinnivan]

Yeah, probably tomorrow

[JakeGinnivan]

Actually, am just doing it now

[JakeGinnivan]

Ok, 3.1.1 is out.

Thank @Philo for the fix

[furrot]

Thanks @JakeGinnivan and @Philo for the quick patch. This fixed the issue I was having.