Proper git settings to stay with master?

[John Hendy <jw.hendy@gmail.com>]

I've not encountered this issue before, but on a git pull last night I
was greeted with a message like this (I don't have the original which
listed several other branches):

$ git pull
From http://orgmode.org/org-mode
   13751c3249..820d1eb617  maint      -> origin/maint
   7fd61c4f92..1c89082600  master     -> origin/master
You are not currently on a branch.
Please specify which branch you want to merge with.
See git-pull(1) for details.

    git pull <remote> <branch>


I just tried =make up0= and get something similar:

$ make up0
rm -f
git checkout
git remote update
Fetching origin
git pull
You are not currently on a branch.
Please specify which branch you want to merge with.
See git-pull(1) for details.

    git pull <remote> <branch>

make: *** [mk/targets.mk:113: up0] Error 1


I don't see anything about this in the FAQ about keeping up to date,
just what I would have done ages ago with a simple =git clone=.[1]

Here's my ~/.elisp/org/.git/config:

$ cat .git/config
[core]
repositoryformatversion = 0
filemode = true
bare = false
logallrefupdates = true
[remote "origin"]
url = http://orgmode.org/org-mode.git
fetch = +refs/heads/*:refs/remotes/origin/*
[branch "master"]
remote = origin
merge = refs/heads/master


Have I botched something? If so, what would be the method to remedy?
If not, what should be updated in the instructions regarding sticking
with master? I see references on how to specify maint, but that seems
to imply that master is the default and action is only required to
override to use maint branch.


Thanks,
John

[1] http://orgmode.org/worg/org-faq.html#keeping-current-with-Org-mode-development