Unreachable merge request

[Raymond Toy]

I was trying to look at
https://gitlab.common-lisp.net/cmucl/cmucl/merge_requests/16 and gitlab
responds with a 500 error.  This was working before the merge happened. 

This merge request still works:
https://gitlab.common-lisp.net/cmucl/cmucl/merge_requests/12

The only thing different that I can tell is that 12 was created by me
and 16 was created by a contributor.


Any ideas?