Bug#900173: git-annex: internal error: evacuate: strange closure type 4325404

[Anthony DeRobertis]

I've tried to reproduce on a newly-installed Buster VM, but haven't
been able to get it to crash. I guess that at least explains why only
I'm complaining — probably something weird about my two workstations
that cause it.

Going to see if I can find it, but welcome any suggestions as to what it
might be.