fatal output from git-show really wants a terminal

[Tim Olsen <tim@brooklynpenguin.com>]

It appears that when outputting a fatal error, git-show will choose
stdout over stderr if stdout is a terminal and stderr is not.  How do I
redirect the error but still allow stdout to be displayed?

~/git$ mkdir test

~/git$ cd test

~/git/test$ git init

~/git/test$ git show 12345

fatal: ambiguous argument '12345': unknown revision or path not in the
working tree.
Use '--' to separate paths from revisions

~/git/test$ git show 12345 2> /dev/null

fatal: ambiguous argument '12345': unknown revision or path not in the
working tree.
Use '--' to separate paths from revisions

~/git/test$ git show 12345 > /dev/null

fatal: ambiguous argument '12345': unknown revision or path not in the
working tree.
Use '--' to separate paths from revisions

~/git/test$ git show 12345 > /dev/null 2> /dev/null

~/git/test$ git show 12345 > /tmp/out 2> /tmp/err

~/git/test$ cat /tmp/out

~/git/test$ cat /tmp/err

fatal: ambiguous argument '12345': unknown revision or path not in the
working tree.
Use '--' to separate paths from revisions