so git annex migrate can switch a file from using one backend to the other.

I've done that with a bunch of files.

The old files should become "unused" right?  But they don't seem to be.  "git annex unused" still shows me only 2 unused files, and I've just migrated dozens of files from SHA256 to SHA256E.  

Is it possible they're still "used" by other repos?  I have two other repos, one reached by SSH and one on a USB drive.  Neither one of them is "bare."  So maybe those files are still used by the "master" branches there, I thought... I went over and did "git annex sync" on each.  Still my newly migrated files are not showing up as "unused."  

I'm worried that my repo is going to bloat with unused files with the SHA256 backend, which mysteriously do not show up as "unused" in git annex unused, if I migrate any more.

any ideas what piece of the puzzle I could be missing here?

