Felix Obenhuber 26f4321a5e
Fix build if not on a git checkout (#119)
Check the exit status of the `git` invocation before parsing the output.
If there's no `.git` the output may look like:

```
fatal: not a git repository (or any of the parent directories): .git
```

and the version shall be set to unknown.
2023-03-22 09:02:16 +01:00
..
2023-03-21 23:18:56 +01:00