https://bugs.winehq.org/show_bug.cgi?id=55710
--- Comment #15 from Zeb Figura z.figura12@gmail.com --- (In reply to Dmitry Timoshkov from comment #9)
Since wine-staging doesn't use --backend=git-am by default and some of the patches in the staging tree have trailing spaces it's impossible to perform a proper git bisect to find the offending patchset.
It doesn't use it by default, but is there anything preventing you from using --backend=git-am manually?