Fwd: Errors when diff'ing arbitrary upstream remotes are not intuitive if git pull --all hasn't been done

Hi!
    I added an arbitrary upstream remote thinking that I could just
git diff the upstream remote's master. Turns out I needed to run git
pull --all in order to be able to diff the file (I forgot that step).
    Could this error message be improved for interactive commands by
first checking to see whether or not the path starts with a remote,
then recommend that the remote be pulled? If this seems sane, I could
whip up a patch and post it in a github pull request.
Thanks!
-Garrett

$ git remote add pkohut [...] $ git diff upstream/master -- conf/ | wc -l 16 $ git diff pkohut/master -- conf/ | wc -l fatal: bad revision 'pkohut/master' 0 $ git pull --all Fetching origin Fetching upstream Fetching pkohut ... $ git diff pkohut/master -- conf/ | wc -l 46 $ git --version; uname -a git version 1.7.9 CYGWIN_NT-6.1 ZL00757 1.7.25(0.270/5/3) 2013-08-31 20:37 x86_64 Cygwin