Installing 7.20190912 from the \"ancient\" tarball at on an x86 Synology NAS, I get

$ git annex merge

Git is older than version 2.22 and so it has a memory leak that affects using unlocked files. Recommend you upgrade git before unlocking any files in your repository. merge git-annex ok git-annex: thread blocked indefinitely in an MVar operation

It seems I messed something up, that build is supposed to have an old git that's patched to work, and with a special version number that git-annex understands will work. --Joey

I don't know what went wrong, other than it was surely several layers of human error. I've updated the tarball, and confirmed it's good now. done --Joey