A stressful thing about maintaining git-annex is that sometimes changes to
git break it in some way. Since git has a high development velocity, it can
be hard to keep up with all changes and catch such problems. The git devs
are good about backwards compatibility, but can still make mistakes. Worse
is when there's an assumption about how people will use git, when git-annex
lets people use it in a rather different way. I've been dealing with one of
those today.

    CONFLICT (file location): x/foo added in refs/remotes/origin/master
    inside a directory that was renamed in HEAD, suggesting it should
    perhaps be moved to y/foo.

This was a interesting new git feature when it was added back in 2.18,
especially since git doesn't really track directories, so is here
somewhat guessing if a directory was renamed.

An example of a way git-annex is used that this does not play well with
is managing media files for consumption, where you might have an incoming
directory, and then rename files to somewhere else once they're processed.
If you renamed the last file in your incoming directory, and then a new
file was later added to it in some other clone of the repository, this git
feature could result in that new file being moved to an unexpected
location when you `git-annex sync`.

Normally it wouldn't matter much if git guessed wrong like that about a
rename, since the merge conflict forces the user to look at it.
But, git-annex sync and the assistant automatically resolve merge
conflicts, so the user can easily not notice this happening.

If you're worried that might have happened to you, look for files in your
repository with ".variant" in the name. If there are two with the same
base name, that's a normal merge conflict, but if there's only a single
variant file by itself, it could have been created by this rename
conflict scenario.

git-annex will now avoid this problem, by setting merge.directoryRenames=false
when running a merge (unless you've manually configured it yourself).

----

Today's work was sponsored by Martin D
[on Patreon](https://www.patreon.com/joeyh)