Obscure error/warning/information message from git pull

[Alan Mackenzie <acm@muc.de>]

Hello, Emacs.

Would somebody please help me with our new wonderfully simple and
elegant version control system.

I have two repositories in directories named .../master and
.../emacs-24, the second having been cloned from the first.

I've done "git pull" in master, and it seems to have worked.  I did "git
pull" in .../emacs-24, and it didn't work.  (Error messages lost).

When I now do "git pull" in .../emacs-24, I get the following
gobbledegook:

    Your configuration specifies to merge with the ref 'emacs-24'
    from the remote, but no such ref was fetched.

Is this an error message, is it a warning, or is merely informational?
I've a vague idea of what "ref" means here (having looked at the git
glossary), but not what "the remote" means (is it referring to the
.../master repository, or is it something within .../emacs-24?).

What does the ungrammatical "specifies to merge with the ref 'emacs-24'"
mean?  What does 'emacs-24' refer to?  Is it the branch within the
repository?  And what are the things, one of them implicit, that are to
be merged here, and where does the result of this merge go?

What about "but no such ref was fetched"?  Fetched from where?  From the
.../master repository, perhaps?

Is this message telling me that there are no changes to .../emacs-24, or
what?  Or is it telling me my configuration is broken?  Here is my
.../emacs-24/.git/config:

   [core]
          repositoryformatversion = 0
          filemode = true
          bare = false
          logallrefupdates = true
   [remote "origin"]
          url = /home/acm/emacs/emacs.git/master/.
          fetch = +refs/heads/*:refs/remotes/origin/*
   [branch "master"]
          remote = origin
          merge = refs/heads/master
   [branch "emacs-24"]
          remote = origin
          merge = refs/heads/emacs-24


I then tried looking at the log in .../master, to see if that might give
me a clue.  Not really.  It just lists a load of commits without saying
which branch they're in.  Does that mean they're all in the master
branch, and there's none in the emacs-24 branch?  This is where version
numbers would have come in handy, to see if there's anything missing.

Then I wanted to list only those those commits in the emacs-24 branch.
Ha!  "git help log" was of no help.  It goes into a man page, and there
is nothing helpful there thus to restrict the display.  There appears
not to be an option such as "-b emacs-24".  There is a "--branches"
option, but what that is supposed to do is completely opaque to me.  How
do I do what I want, here?

Thanks for the help!

-- 
Alan Mackenzie (Nuremberg, Germany).