Every few months, I get grumpy when my "git branch -a" command fills up the screen and it looks like there is a bunch of branches that are not being worked on, or that have been merged, or can otherwise be archived. So, I will move the "dead wood" branches from the branches to tags.

What gets bag-n-tagged

I just run a script that looks for branches that are more than 90 days old: 

git for-each-ref --format='%(refname)' refs/remotes/origin | {
    exp=$(( $(date +'%s') - 7776000 ));
    while read ref; do
        if test ${exp} -gt $(git show -s --pretty=format:'%ct' $ref); then
            echo $ref
        fi
    done;
}

I then email htcondor-devel to politely ask if I can bag-n-tag the branches listed.

When a branch gets bag-n-tagged

I create a tag with the name of the branch, ending in "-tag". So branch "foo" will get tagged with tag "foo-tag". I run the following git commands 
git tag -a -m "Bag-n-tag branch foo" foo-tag foo # To create the foo-tag tag
git push origin tag foo-tag # To publish the new tag
git push origin :refs/heads/foo # To delete the branch

How to resurrect a branch

If a branch is overzealously deleted, it is easy to restore. You may still have the old reference around, so you could run 
git push origin refs/remotes/origin/foo:refs/heads/foo
to simply copy the old reference back to the condor repository

If you have only the tag, you can do the following 

git branch foo foo-tag^{}
git push origin foo:foo
to restore the branch.

Here is the actual script: 

#!/bin/bash

GIT_DIR=/p/condor/repository/CONDOR_SRC.git
export GIT_DIR

bag_n_tag() {
        trimmed_branch_name=$(echo $1 | sed 's|^refs/remotes/origin/||;s|^refs/heads/||')
        origin_ref=refs/remotes/origin/${trimmed_branch_name}
        cat <<TAGCOMMANDS
git tag -a -m "Bag-n-tag branch ${trimmed_branch_name}" ${trimmed_branch_name}-tag "${origin_ref}" || { echo "Failed to create tag ${trimmed_branch_name}-tag"; exit 1; }
git push origin tag ${trimmed_branch_name}-tag || { echo "Failed to push tag ${trimmed_branch_name}-tag to origin"; exit 1; }
git push origin :refs/heads/${trimmed_branch_name} || { echo "Failed to delete branch ${trimmed_branch_name} from origin"; exit 1; }
TAGCOMMANDS
echo
}

ctime=$(date +'%s')
ctime=$(( $ctime - 7776000 ))
git for-each-ref refs/heads | while read sha1 type refname
do
#       echo $refname
        branchname=$(if test "$type" != "commit"; then
                exit 0
        fi
# This should never happen, but being paranoid...
        if echo "$refname" | grep -qE 'refs/tags'; then
                exit 0;
        fi
        commitdate="$(git log --pretty=format:'%ct' -1 $sha1)"
        if test "$commitdate" -gt "$ctime"; then
                exit 0;
        fi
        echo $refname)
        if test -n "$branchname"; then
                bag_n_tag "$branchname"
        fi
done
The following script accepts output from the above program and produces a readable output that can be emailed to htcondor-devel: 
#!/bin/bash

grep '^git tag' | \
sed 's/.\+refs\/remotes\/origin\//refs\/remotes\/origin\//;s/ ||.\+//' | \
while read ref; \
         do echo "${ref##*/} $(git rev-list --count --left-right origin/master...${ref} | awk '{if($2 == "0") print "merged"; else print "unmerged"}') $(git log -1 --pretty=format:'%ct %an' $ref)"; done | \
sort -k2,2 -k4 | \
while read branch status authd author; \
        do printf "%-45s %10s %s %s\n" "$branch" "$status" "$(date -d @$authd +'%F')" "$author";
done