Update to git 2.17 breaks a little

[slackhead]

The error message that is printed when not in a git repo has changed from:

fatal: Not a git repository to
fatal: not a git repository

Which causes gitstatus.py to output garbage results. Easy fix is to compare using .lower()

[fam4r]

Please see here: #103

[juanibiapina]

A better option is to compare the status code:

if gitsym.returncode != 0:
        sys.exit(0)

[fam4r]

Yes, that has been discussed in #103 and there's a PR in #119 , just in case you want to join the thread 😄