Ah, I missed your commit message.

I tried it out independently in IRB and I also noticed the `nil` returned by `system` when the command is not found. I propose to address this by adding a message to the `abort` (see my comment above). I appreciate that the current solution gives more detailed information, but I am not sure if the added detail is worth the extra code and tying this script more tightly to `lib/gitlab_config.rb`.