Jeff King [off-list ref] writes:
I don't buy the "gitk should be read-only" argument from that thread. I
think we decided a while back[1] that the stat cache is not really a
user-visible modification; you're not updating the index in any
meaningful way that impacts the user's workflow, but merely refreshing
our cache of what is in the filesystem.
I think it is OK as long as a failure to "update-index --refresh"
does not lead to a user-visible error (I think we made sure that the
the opportunistic refresh "git diff" and "git status" does won't
report an error, when you are trying to help your co-worker by
visiting her repository and running these commands, only to peek).