refname is ambiguous and pull failing

Question

I ran the following command as I wanted to move my production branch back without having to checkout first:

git branch -f production HEAD~1

I am now getting the following warning when I checkout production:

warning: refname 'production' is ambiguous.

I then run:

git pull

And I receive the following error:

First, rewinding head to replay your work on top of it...
Fast-forwarded production to 7463e01c536ad52746b8879ef3d70ffd5a8db31e.
error: Ref refs/heads/production is at 252038dfa22caba8a816a68dcb005c625e44c51f but expected ae5b621609c1b5b430e3d30711157298f842942a
fatal: Cannot lock the ref 'refs/heads/production'
Could not move back to refs/heads/production

I can pull on other branches though. How can I fix this?

Further Info

git tag doesn't return any output. I previously had a production repository, but I've now renamed it to live

> ~/repo (chris-membership-fees)$ git show-ref | grep production
88e0c37c9ae4ff6967ddd027b62b62fa2c0ac272 refs/heads/production
9d739cff44a898f0c68da33fb22a230985e479ce refs/remotes/backup/production

~/repo (chris-membership-fees)$ git branch -a | grep production
  production
  remotes/backup/production

Log

I tagged the first revision as a and the second as b (note that the revision numbers have changed as production is now different). This is the log, simplified by decoration

* commit 7463e01c536ad52746b8879ef3d70ffd5a8db31e (**tag: a**, backup/live-master, production, live-master)
| 
| Date:   Wed Dec 28 11:47:49 2011 +1100
| 
|     Merge remote-tracking branch 'origin/joseph-quick-fix'
|  
* commit f35f0259c4e36d46dd1df71b3293bef6105cef98 (origin/hotfix-googleplusdirectconnect)
| 
| Date:   Fri Dec 23 12:25:27 2011 +1100
| 
|     Add google plus link tag to home page for direct connect
|    
*   commit 8b3a30ef2909439ac18b65ebbb316eb0cdd2d61c
|\  Merge: f696f3e 88e0c37
| | 
| | Date:   Wed Dec 21 14:28:45 2011 +1100
| | 
| |     Merge branch 'master' into chris-hotfix
| |   
* | commit f696f3e2b8f4a19ec2b2c2a3638c68e7a52836e3 (origin/chris-hotfix, backup/chris-hotfix, chris-hotfix)
| | 
| | Date:   Wed Dec 21 11:56:10 2011 +1100
| | 
| |     Fixed buyer price info
| |     
| *   commit 88e0c37c9ae4ff6967ddd027b62b62fa2c0ac272
| |\  Merge: c9655da ae5b621
| |/  
|/|   Date:   Wed Dec 21 11:53:36 2011 +1100
| |   
| |       Merge branch 'master' of git.freelancer.com:production into production
| |   
* | commit ae5b621609c1b5b430e3d30711157298f842942a (HEAD, **tag: b**)
| | 
| | Date:   Wed Dec 21 10:51:47 2011 +1100
| | 
| |     Merge branch 'master' of git.freelancer.com:production
| |   
| * commit c9655da9c1627ab53720ae818affdd1e6f14119f (origin/game-shadow2)
| | 
| | Date:   Tue Dec 20 18:41:57 2011 -0500
| | 
| |     * Removed debugging code
| |     
| *   commit ca88d33538bd3b99ea7c186b5b531e611847989d
| |\  Merge: 99e983a c397a8b
| |/  
|/|   Date:   Tue Dec 20 17:25:24 2011 -0500
| |   
| |       Merge remote-tracking branch 'production/master' into shadow2

Answer 1

If you just want to remove the warning:

git config --global core.warnambiguousrefs false

The warning is coming because you have a branch named production and also a remote named production. It will be ideal to rename either of the two to something else.

Answer 2

> ~/repo (chris-membership-fees)$ git show-ref | grep production
88e0c37c9ae4ff6967ddd027b62b62fa2c0ac272 refs/heads/production
9d739cff44a898f0c68da33fb22a230985e479ce refs/remotes/backup/production
88e0c37c9ae4ff6967ddd027b62b62fa2c0ac272 refs/remotes/production/master

refs/heads/production is ambiguos due to refs/remotes/production. Resolution is generic and independent of the reference-type prefix, thus branches, tags, remotes and even custom ref names must not collide.

Answer 3

Thanks to Johannes Sixt on the Git mailing list.

The most likely reason is that you have a ref 'production' directly in the .git directory. Perhaps you or one of your scripts created it accidentally using 'git update-ref production ae5b621', i.e., without giving the full ref path name

It wasn't actually in the .git root directory, but I had an empty production folder in branches.