Diagnosed why git log in the plum-cliff mono worktree showed only commit 2798c6f3.
Confirmed the shared repository was shallow and that 2798c6f3 was listed as a shallow boundary, despite its commit object naming parent a60f7926.
Ran git fetch --unshallow origin against the shared mono repository.
Verified the repository is no longer shallow and that 486 commits are reachable from the branch head.
Lessons Learned: Pitfalls
Linked worktrees share the main repository’s object database and shallow metadata. A depth-limited fetch performed for one branch can therefore make history appear truncated in another worktree.
git show or ordinary revision traversal can hide a real parent at a shallow boundary. git cat-file -p HEAD is useful for confirming the raw parent header.
Lessons Learned: Improvements
When git log unexpectedly stops at one commit, check git rev-parse --is-shallow-repository before investigating force-pushes or orphan branches.
For linked worktrees, use git rev-parse --git-common-dir to find and inspect the shared shallow file.
