Hi Greg,
This happens if the git repo on VFB doesn't have tags pulled. You can reproduce this by initializing a bare git repo, adding the catmaid github as a remote repo, then fetching with the `--no-tags` option.
What's also interesting is that your `git describe` example does not match mine (I get `2018.04.15-288-g1bf6740`).
Running `git fetch --tags` should fix the acute problem, but there's probably some issue with either the `fetch` or `tagopt` git config for the github remote on the VFB server.
Best,
Andrew