On Thu, Mar 22 2018, Konstantin Ryabitsev wrote: > What is the most efficient way to test if repoA and repoB share common > commits? My goal is to automatically figure out if repoB can benefit > from setting alternates to repoA and repacking. I currently do it by > comparing the output of "show-ref --tags -s", but that does not work for > repos without tags. If you're using show-ref already to get the tag tips, you can use for-each-ref to get all tips. But of course that'll just give you the tips. You could then use `git cat-file --batch-check` on both ends to see what commits from the other they report knowing about, in case they have branches that are ahead/behind the other.