Björn Steinbrink [off-list ref] writes:
Hm, not sure if I'd call it "better", but probably at least a bit
faster. You could create a "fake" merge to combine all the branches.
git branch -r --no-merged $(
: | git commit-tree HEAD^{tree} $(
git for-each-ref --format='-p %(refname)' \
refs/heads/ \
refs/remotes/origin
)
)
Heh, that is certainly a cute hack ;-)