gitlib offers a debug mode, to make you see edge-cases of your usage. This is called debug-mode.
Debug-mode is enabled by default. If you disable it, gitlib will behave differently:
If you want to disable exceptions and try to minimize as much as possible errors, pass false when construction a repository:
$repository = new Gitonomy\Git\Repository($path'/tmp/repo', $debug = false)
$debug argument should be available in every method you can use to create a repository.