stale remote branches are not cleaned from upstream references

Question

When invoking meld inside a git repo, I get a bunch of warnings before meld opens :

# from within a git repo :
$ meld .
fatal: bad revision '^origin/branch/one'
fatal: bad revision '^origin/branch/two'
fatal: bad revision '^origin/branch/three'
...

This is just a warning printed on STDERR, meld runs fine afterwards and displays the expected diff.

Most of these branches have a local checkout, but no matching remote reference on origin.
One of these references doesn't even exist locally (it is one misspell away from an existing branch).

Does someone know I could dispose of these disgraceful messages ?

Answer 1

The problem was in my repo configuration.

Some local branches were still tracking stale remote branches :
the .git/config file still contained sections :

[branch "branch/one"]
    remote = origin
    merge = refs/heads/branch/one

even though the remote branch branch/one did not exist anymore, and my local reference origin/branch/one was (correctly) deleted.

I didn't find any direct command to clean my local branches up.
I was hoping git remote prune origin would clean this up, but it didn't.

Here is a way I found to have my local branches stop tracking stale remote branches :

# enumerate all local branches, and print "branchname upstreamname" :
git for-each-ref --format="%(refname:short) %(upstream:short)" refs/heads |\

# keep branches which track a remotre branch in origin :
grep "origin/" |\

# loop on output :
while read local remote; do
  # use any command which fails on an invalid ref :    
  if ! git show $remote -- &> /dev/null then
    # if it failed : stop tracking this stale remote
    git branch $local --unset-upstream
  fi
done