omo's omo-agent-toolkit worktree-sweep (their PR #7151) added three
capabilities our hermes worktree command lacked:
- --json on list and prune: machine-readable audit/result payloads so
scripts and agents can consume verdicts without scraping table output.
- --older-than DAYS: an age floor that only ever RESTRICTS reaping
(young-but-reapable trees are kept); it never widens eligibility, so
the existing safety invariants are untouched.
- External-tree visibility: linked worktrees registered outside
.worktrees/ are now reported read-only in the audit (branch, locked,
missing) instead of being invisible, and registrations whose
directory has vanished are dropped via git worktree prune (metadata
only, no files touched) during prune.
Not ported: omo's ancestor-of-default-branch merge test (our git cherry
patch-equivalence is strictly stronger under rebase/squash merges), and
their hardcoded external-root exclusion list (we exclude by location:
everything outside .worktrees/ is hands-off).
Tests: 9 new contracts in tests/hermes_cli/test_worktree_gc.py (age gate
restrict-only, external trees never reaped, stale-registration prune
dry-run/real, JSON shapes, negative --older-than rejected). Live E2E on
a scratch repo verified all three flags end to end.
The startup pruner is deliberately conservative (unattended, pre-banner),
so real installs accumulate what it can never touch: trees preserved for
untracked-only scratch, and orphaned local branches beyond the two
auto-generated prefixes it deletes. A measured multi-agent box: 35 trees /
15GB / 244 local branches, 120 of them fully merged.
New attended surface (hermes_cli/worktree_gc.py + worktree_cmd.py):
- hermes worktree list — audit every tree: age, size, verdict, reason,
plus deletable-branch count
- hermes worktree prune [--dry-run|--trees-only|--branches-only]
- /worktree prune [--dry-run] — same engine in-session; never touches the
session's own active tree
- startup escalation: one WARNING when .worktrees/ exceeds 10 trees or
5GB, naming the reclaim commands (silence is how boxes hit 15GB)
Safety invariants (shared with the startup pruner via cli.py primitives):
tracked modifications and unique unpushed commits never deleted at any
age; live-locked trees untouched; branch deletion gated on worktree
removal success; untracked-only scratch ARCHIVED to
~/.hermes/archive/worktree-prune/ before its tree is reaped.
Branch GC is content-gated, not name-gated: any local branch fully merged
or git-cherry patch-equivalent upstream is safe to delete (rebase merges
rewrite SHAs, so --merged alone misses the dominant leak); unique-commit,
checked-out, protected, and stale-base (>50 ahead) branches are kept.
Classification is parallel (8 workers) — 244 branches audit in ~64s live.
git timeouts degrade to keep (returncode 124) instead of crashing the
audit — live-verified failure on a 746MB .git repo.
16 behavior-contract tests against real git fixtures; live dry-run on the
production repo: 12 trees reclaimable, 120 branches deletable, 0 false
positives among kept trees.
