Adoption moved the canonical settings.json aside with rename() and left
the path empty until publication, roughly 100 ms later. Claude Code or a
second `ccs` starting inside that window found no file and seeded an
empty placeholder; publication then failed with EEXIST because link() is
no-replace, and the rollback published a backup and unlinked the claim,
destroying the only remaining copy of the user's settings. Recovering
meant digging through sidecar files by hand.
Publish by replacement instead: write a temp file next to the canonical
inode and rename() it over the target, so the path always holds a regular
file and no placeholder can be seeded. A compare-and-swap guard on
(ino, mtime, size) runs immediately before the rename and refuses to
publish when the canonical inode changed since it was read, so a writer
that got there first is still never clobbered. The pre-image backup is
published before the replacement, keeping the old content recoverable if
publication is interrupted.
Drops the canonical claim entirely along with restoreCanonicalClaim, and
folds the two identical sidecar publishers into one helper.
recoverOrphanedCanonicalClaim stays, since claims written by older
versions may still be on disk.
New tests cover both writers seen in the incident: Claude Code seeding
`{}` with a trailing newline, and a second `ccs` seeding the 2-byte
variant from shared-dir-linker. Four tests that pinned the claim-based
design were rewritten, among them `preserves a canonical write that
lands during no-replace publication`, whose intent is now enforced by
the CAS guard instead of by an EEXIST from a no-replace link.
Built [OnSteroids](https://onsteroids.ai)
The same atomic-rename divergence occurs in the plugins subtree: a
plugin install inside a session rewrites plugins/installed_plugins.json,
replacing the instance-level symlink with a regular file. The per-launch
relink then discarded it, so the plugin was effectively uninstalled on
every relaunch while settings.json still marked it enabled — sessions
then fail with 'Unknown skill: <plugin>:<skill>'.
Move adoptDivergedFileContent to fs-helpers (avoids a circular import)
and apply it to file-type plugin entries before re-linking.
Claude Code saves settings.json atomically (temp file + rename), which
replaces the managed shared symlink with a regular file holding the
user's latest changes (see #57). The launch-time relink then deleted
that file without reading it, silently reverting plugin enables and any
other in-session settings change on every profile relaunch.
Adopt the diverged file's content into the canonical ~/.claude file
(with a .bak-ccs-adopt backup) before restoring the symlink, at both
the shared-level and instance-level reconciliation points.
Fixes#1681
Claude Code's marketplace auto-update uses a three-step atomic rename:
clone to <name>.staging → rename old dir to <name>.bak → rename staging
to the final name. On Windows, EPERM errors can interrupt the rename-dance
and leave a <name>.staging directory permanently on disk.
CCS scanned physical directories to discover marketplaces, so a lingering
.staging directory was registered as a bare { installLocation } entry in
known_marketplaces.json. Claude Code's Zod schema requires each entry to
also have `source` and `lastUpdated` fields, so the corrupt entry caused
the /plugin command to throw a validation error.
Fix (two layers of defence):
- discoverMarketplaceEntries: skip any directory whose name starts with
'.' or ends with '.staging'. This filters all hidden dirs including
.staging and .bak left behind by interrupted rename operations.
- buildMarketplaceRegistryContent: invert the loop direction. Instead of
iterating discoveredEntries and adding to the registry (which could
introduce bare entries for disk-only directories with no registry
record), iterate the merged registry and only keep entries that also
exist on disk. Disk-only directories are now silently ignored.
Adds two regression tests: one for .staging pollution, one for orphan
registry entries whose physical directory has been removed.
- detach verified shared symlinks when a profile is reopened as bare
- prune stale marketplace entries whose payload directories no longer exist
- add regressions for bare/non-bare transitions and stale registry recovery
- keep bare and non-bare marketplace normalization inside the plugin-layout lock
- warn when malformed registry sources are skipped during reconciliation
- add regression coverage for cross-instance refresh metadata and legacy layout upgrade
Sergey Galuza