Ugly NullReferenceException if not in a git repo

[roji]

The following seems a bit much (GitVersion 1.0.0.1):

C:\>gitversion
INFO [05/06/16 13:41:29:08] Working directory: C:\
ERROR [05/06/16 13:41:29:11] An unexpected error occurred:
System.NullReferenceException: Object reference not set to an instance of an object.
   at GitVersion.GitPreparer.GetDotGitDirectory()
   at GitVersion.ExecuteCore.ExecuteGitVersion(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()
INFO [05/06/16 13:41:29:11]
INFO [05/06/16 13:41:29:11] Here is the current git graph (please include in issue):
INFO [05/06/16 13:41:29:11] Showing max of 100 commits
INFO [05/06/16 13:41:29:17] ERROR: fatal: Not a git repository (or any of the parent directories): .git

[dazinator]

Yep I just reproduced this using the latest GitVersion.Portable chocolatey package. (GitVersion 3.5.2).

Ran into it because I was configuring Team City step, and hadn't switched to "Agent Checkout". Agree that the error message here should be nicer :)

[asbjornu]

Should be fixed in #860.