git errors pulling notmuch

[Tomas Nordin]

Hello Notmuchers

I have installed Notmuch from source a while ago and been happy. But
today I thought maybe it is about time to see if I should update (244
commits behind), so I tried to pull the changes. I am getting this git
error:

  1 git … pull origin
error: cannot lock ref 'refs/remotes/origin/debian/jessie-backports': 'refs/remotes/origin/debian' exists; cannot create 'refs/remotes/origin/debian/jessie-backports'
>From git://notmuchmail.org/git/notmuch
 ! [new branch]        debian/jessie-backports -> origin/debian/jessie-backports  (unable to update local ref)
error: cannot lock ref 'refs/remotes/origin/debian/squeeze-backports': 'refs/remotes/origin/debian' exists; cannot create 'refs/remotes/origin/debian/squeeze-backports'
 ! [new branch]        debian/squeeze-backports -> origin/debian/squeeze-backports  (unable to update local ref)
error: cannot lock ref 'refs/remotes/origin/debian/stretch': 'refs/remotes/origin/debian' exists; cannot create 'refs/remotes/origin/debian/stretch'
 ! [new branch]        debian/stretch          -> origin/debian/stretch  (unable to update local ref)
error: cannot lock ref 'refs/remotes/origin/debian/stretch-backports': 'refs/remotes/origin/debian' exists; cannot create 'refs/remotes/origin/debian/stretch-backports'
 ! [new branch]        debian/stretch-backports -> origin/debian/stretch-backports  (unable to update local ref)
error: cannot lock ref 'refs/remotes/origin/debian/wheezy-backports': 'refs/remotes/origin/debian' exists; cannot create 'refs/remotes/origin/debian/wheezy-backports'
 ! [new branch]        debian/wheezy-backports -> origin/debian/wheezy-backports  (unable to update local ref)

the output is via Magit process. The currently installed notmuch is
0.24.1+65~g77c9ec1

Do you see easy what's going on?

Best regards
--
Tomas