From: Toon Claes Date: Wed, 03 Jun 2026 13:44:11 GMT Subject: Re: Suggetsions for collaboration workflows in large repos Message-ID: <87tsrj20yc.fsf@emacs.iotcl.com> In-Reply-To: Matthew Hughes writes: > On Fri, May 29, 2026 at 05:31:17PM +0100, Matthew Hughes wrote: >> I thought about doing something like tracking >> `refs/heads*/some-colleague-branch` from the remote, since with the wildcard >> `*` I at least won't the fatal error on the missing reference during fetch, but >> that risks my config containing an ever growing list of such wildcards, or a >> bunch of manual work occasionally cleaning up old ones (or maybe that could be >> automated). I feel your problem, although a lot less in the project I'm working on lately. I have these refspecs by the way: fetch = +refs/heads/master:refs/remotes/origin/master fetch = +refs/heads/toon-*:refs/remotes/origin/toon-* > I hacked some scripts to automate this. Firstly, one for fetching: > > 1. Fetches the branch > 2. Adds a fetch config with wildcard hacks so `git fetch` brings in updates for > that branch (the refspec should match _exactly_ that branch and never > anything more) > 3. Adds a separate ref to record that we're tracking this branch (so something > knows to clean it up later) > > #!/usr/bin/env bash > > set -o errexit -o pipefail -o nounset > > # save command as e.g. git-fetch-other > CMD_NAME="$(basename "$0" | sed 's/git-//g')" > if [ $# -lt 1 ] > then > echo "usage: git $CMD_NAME branch-name [ remote-name ]" >&2 > exit 1 > fi > > BRANCH_NAME="$1" > REMOTE_NAME="${2:-origin}" > FETCH_CONFIG_NAME="remote.$REMOTE_NAME.fetch" > > git fetch "$REMOTE_NAME" "$BRANCH_NAME" > git checkout -b "$BRANCH_NAME" > > # we want to record that we are tracking this branch, to do this create > # a new ref whose name tells us what we're tracking, but whose value is > # unimportant. So as a placeholder value just use the hash of an empty tree > # taken from https://git.kernel.org/pub/scm/git/git.git/commit/?id=9c8a294a1ae1335511475db9c0eb8841c0ec9738 > EMPTY_TREE_REF="$(git hash-object -t tree /dev/null)" > > # refspec used to track the branch: we expect branches to be deleted from the > # upstream when merged so tracking exactly: > # "+refs/heads/$BRANCH_NAME:refs/remotes/$REMOTE_NAME/$BRANCH_NAME" will error > # when we go to fetch that exact ref after its removed upstream. > # so HACK around this: add wildcards that we still expect to only ever match > # this exact branch (but doesn't have the issue of git complaining when it > # tries to fetch an _exact_ ref) > TRACKING_REFSPEC="+refs/heads*/$BRANCH_NAME:refs/remotes*/$REMOTE_NAME/$BRANCH_NAME" > > # record that we're tracking this branch. First check we've not already > # recorded this, then ... > if ! git config get --local --fixed-value --value "$TRACKING_REFSPEC" "$FETCH_CONFIG_NAME" >/dev/null > then > # ... set the config to track it for fetching, and ... > git config set --comment "$CMD_NAME: tracking at $(date -I)" --local --append "$FETCH_CONFIG_NAME" "$TRACKING_REFSPEC" > # ... record that we have special cased this tracking > git update-ref "refs/tracked/$REMOTE_NAME/$BRANCH_NAME" "$EMPTY_TREE_REF" > fi It seems to be a bit more advanced than the alias I have: cofetch = !sh -c 'git fetch $1 $2:remotes/$1/$2 && git switch -c $2 remotes/$1/$2' - You need to pass it the remote and the branch name (in reverse order of yours, which makes sense if you want the remote to be optional). > And the cleanup script (needs to be run periodically): > > 1. Collects all the remote branches we know about > 2. Checks all the references from step 3. above and checks if any branches > defined there are missing remotes (I have fetch.prune=true to keep the remote > tracking references up-to-date) > 3. If they are, drops the tracking config for that branch > > #!/usr/bin/env bash > > set -o errexit -o pipefail -o nounset > > REMOTE_NAME="${1:-origin}" > TRACKED_REF_PREFIX="refs/tracked/$REMOTE_NAME" > REMOTE_REF_PREFIX="refs/remotes/$REMOTE_NAME" > > declare -A remote_branch_lookup > while read -r remote_ref > do > # strip prefix, e.g. 'refs/remotes/origin/some-branch' -> 'some-branch' > branch_name="${remote_ref#$REMOTE_REF_PREFIX/}" > remote_branch_lookup["$branch_name"]=1 > done < <(git for-each-ref --format='%(refname)' "$REMOTE_REF_PREFIX/") > > while read -r tracking_info > do > tracked_branch="${tracking_info#$TRACKED_REF_PREFIX/}" > if ! [[ -v "remote_branch_lookup[$tracked_branch]" ]] > then > echo "branch $tracked_branch has been removed from the remote, untracking it" > git update-ref -d "$TRACKED_REF_PREFIX/$tracked_branch" > > tracking_refspec="+refs/heads*/$tracked_branch:refs/remotes*/$REMOTE_NAME/$tracked_branch" > git config unset --local --fixed-value --value "$tracking_refspec" "remote.$REMOTE_NAME.fetch" > fi > done < <(git for-each-ref --format='%(refname)' "$TRACKED_REF_PREFIX/") > > So functionally I think this allows for the workflow I want, but does feel like > a big ol' hack :> I agree it feels hacky, but I don't really see how we can generalize it more so it will become a standard feature in git? I was thinking you can already pass `-c remote.origin.fetch=` (multiple times) to git-clone(1), but in practice it doesn't seem to work because that config is additive, so it adds the refspec, instead of overwriting, so you're getting: fatal: multiple updates for ref 'refs/remotes/origin/main' not allowed And you cannot combine it with `--single-branch`, although you could do a single branch clone and then add additional refspecs later. -- Cheers, Toon