Radicle with JJ

Make jj git push work for patches by other authors

Setup

Tell jj that main on the rad remote is the trunk. Run this command in the repository:

jj config set --repo 'revset-aliases."trunk()"' 'main@rad'

The alias must point to the default branch of the repository. If the default branch has another name, for example master, replace main with that name.

Problem

You check out a patch that another person opened, add commits, and push the patch bookmark with jj:

rad patch checkout 190113b
jj bookmark track patches/190113b8a709a368b7471f4a4b403fa50e909976@rad
jj bookmark set patches/190113b8a709a368b7471f4a4b403fa50e909976 -r @-
jj git push --remote rad --bookmark patches/190113b8a709a368b7471f4a4b403fa50e909976

The push fails:

Warning: The following references unexpectedly moved on the remote:
  refs/heads/patches/190113b8a709a368b7471f4a4b403fa50e909976 (reason: stale info)

A fetch from rad does not fix it. A plain git push rad <oid>:refs/heads/patches/<id> works.

The patch COB already lets anyone add a revision (Action::Revision { .. } => Authorization::Allow in crates/radicle/src/cob/patch.rs). So this is only a remote helper problem, not a permission problem.

Cause

The remote helper gives git different ref lists for fetch and push (crates/radicle-remote-helper/src/list.rs):

• for_fetch lists special refs, refs/heads/patches/<id>. Each one points to the head of the latest revision of an open patch (patch_refs). jj imports these, so patches/<id>@rad points to the other author’s head.
• for_push lists only the refs/heads/* and refs/tags/* refs in your own namespace. Your namespace has no refs/heads/patches/<id> for a patch you did not push.

jj always pushes with --force-with-lease=<ref>:<expected-oid>, where the expected OID is the value it got from the fetch. Git compares this value with the list for-push output. The ref is not in that list, so git rejects the push with “stale info” before the helper receives it.

Plain git push sends no lease. The ref is not in your namespace, so git treats the push as a new ref and accepts it.

There is a second problem behind the first one. Git sends each lease to the helper as option cas <ref>:<oid>. main.rs collects these in expected_refs. Then push_ref in push.rs passes every entry to git send-pack as --force-with-lease=refs/namespaces/<your-nid>/<ref>:<oid>. For a patch ref, this compares the expected OID with your namespace, not with the patch. So a fix to the ref list alone moves the failure into send-pack.

Workaround: use a self remote

Add a second remote that points to your own node. Then rad is the read-only remote and self is the remote you push to. This is the usual git split between a “master” remote and a “developer” remote.

rad remote add --name self $(rad node status --only nid)

Your node must run when you use this command.

• Fetch from rad. Push to self: jj git push --remote self --bookmark patches/<id>.
• The push to self has no stale lease, because your namespace holds the ref.
• With self, jj git fetch --remote rad no longer abandons the commits of a revision that you pushed.

The rad remote works as designed. A non-author must not move the head of a patch, so rad shows the head of the latest revision by the patch author. The change below makes jj git push --remote rad work too.

Source: Zulip thread.

Fix jj git fetch tag bookmarks that flap

Problem

Each jj git fetch --remote rad prints a warning. The tags/releases/*@rad bookmarks are deleted on one fetch and created again on the next:

Warning: Ignored refspec `+refs/tags/*:refs/remotes/rad/tags/*` from `rad`: only refs/heads/ is supported for refspec sources
bookmark: tags/releases/0.10.0@rad [deleted] untracked

Cause

The rad remote has two fetch refspecs. Check them with git config --get-all remote.rad.fetch:

+refs/heads/*:refs/remotes/rad/*
+refs/tags/*:refs/remotes/rad/tags/*

The second refspec means: copy every remote tag to refs/remotes/rad/tags/*, and allow the copy to move when the remote tag moves. It keeps remote tags apart from your own local tags.

jj only supports refspecs that start at refs/heads/. It ignores the tag refspec and prints the warning. But jj reads every ref under refs/remotes/rad/ as a remote bookmark. So the tag copies become tags/releases/*@rad bookmarks.

The bookmarks flap because of two steps in each fetch:

• jj fetches tags itself. Git sees the tag refspec in the config and also writes copies of these tags to refs/remotes/rad/tags/*.
• jj prunes the refs under refs/remotes/rad/ that its own refspec does not cover. This deletes copies from earlier fetches.

A plain git fetch rad also creates all the copies again.

Fix

Remove the tag refspec and the tag copies:

git config --unset-all remote.rad.fetch '^\+refs/tags/'
git for-each-ref --format='%(refname)' refs/remotes/rad/tags | xargs -n1 git update-ref -d
jj git fetch --remote rad

Your local tags in refs/tags/releases/* stay. They do not depend on this refspec.

What changes

• The warning and the flapping bookmarks stop.
• jj 0.44.0 still fetches tags into refs/tags/*. This includes new tags, tags on commits outside the fetched branches, and tags that moved on the remote. These tags show as tag: <name>@rad in the fetch output.
• Plain git fetch rad fetches only new tags that point to fetched commits. This is tag auto-following. It is the git default. remote.rad.tagOpt controls it. It is unset here.
• With git, a tag that moved on the remote is not updated, because the + rule is gone. git fetch rad --tags rejects it with “would clobber existing tag”. Run git fetch rad --tags --force to update it.
• A Radicle command may add the refspec again. The source is not confirmed. Likely candidates are rad init, rad clone and rad remote add.

Create and push a tag

With jj

jj 0.44.0 can create and push tags:

jj tag set releases/0.17.0 -r <rev>
jj git push --remote rad --tag releases/0.17.0

• jj tag set creates a lightweight tag. jj cannot create annotated tags, which carry a message.
• --tag accepts glob patterns, for example --tag 'releases/*'.
• A bare jj git push also pushes tags in the default revset (remote_bookmarks(remote=rad)..@). --all pushes all bookmarks and tags. Use it with care on rad.
• The push of a tag through the rad remote helper is not tested. If it fails with a lease or “stale info” error, as patch pushes do, use git.

With git

Radicle release tags such as releases/0.16.0 are annotated. Create them with git:

git tag -a releases/0.17.0 -m "Release 0.17.0" <commit>
git push rad tag releases/0.17.0

• With jj, @ is usually an empty working-copy commit. Tag the commit you want to release. Find its hash with jj log.
• jj imports the new tag on the next command.
• The push goes to your own namespace. The tag becomes canonical when enough delegates have the same tag. With one delegate, this happens at once.
• Run jj git fetch --remote rad or git fetch rad to see tags from other delegates.