A stamp-shaped directory name is not ownership proof: pruneSkillBackups
counted and RemoveAll'd any 20260819-120000-shaped entry under
~/.dws/skill-backups, so a user or tool that created such a directory
lost its contents once DWS held five backups, and the Go backup path
(MkdirAll) adopted a same-named foreign root outright. The PowerShell
installers already implemented the correct contract; every other
surface now matches it.
Go stamps a freshly created root with the exact marker bytes the
install scripts write (.dws-skill-backup = "dws skill backup v1")
before any payload moves in, claims the root with mkdir so an existing
unproven root bumps to a collision suffix instead of being adopted,
and prunes only roots whose marker verifies — unmarked or wrongly
worded stamp-shaped directories are foreign data, preserved and never
counted against the keep limit. The shell installers (install.sh,
install-skills.sh, install-event.sh, install-devapp.sh) and the npm
installer apply the same rule in their backup collision loops, with
roots recorded as created by the running process exempt from marker
re-verification so a mid-run marker permission failure still reuses
this run's own root and keeps the sibling payload intact.
Regression tests cover every surface: pruning an unmarked/wrongly
marked stamp-shaped directory alongside marked ones, refusing to adopt
a foreign root (payload moves to a suffixed root, foreign data and its
nonexistent marker untouched), same-stamp reuse of a proven root, and
marker-write failure cleaning the empty fresh root.
Match the Go dest-first identity check so a concurrent replacement is
never moved into .rollback-*; only a post-quarantine mismatch is
restored with no-replace. Cover both races in the npm smoke suite.
Record dest on occupy and retract it when confirmation, verify, or
staging cleanup fails. Restore unmatched quarantine with a no-replace
publish. Event/devapp copy uses mkdir-claim; shell rollback claims dest
before delete. Release copy now says npm/PowerShell create junctions and
Go uses os.Symlink, with copy fallback when linking is unavailable.
publishCanonicalLinkNoReplace checked the destination with lstat and
then published, leaving a window the comment claimed did not exist: on
Windows renameSync replaces a concurrent object outright (libuv passes
MOVEFILE_REPLACE_EXISTING), and on POSIX ln -P source target links INTO
a directory that appeared at the target, leaving a stray link inside
foreign data that the rollback list never recorded. Create the symlink
or junction directly at the destination instead — link creation fails
with EEXIST when anything occupies the path and never treats the target
as a container, so the publication itself is the atomic no-replace
check. Identity confirmation re-reads the live link before the
publication enters the rollback list. Covered by injected concurrent
creators at the publish instant on POSIX and simulated Windows,
asserting the foreign object and its contents stay completely
unchanged.
The mono and multi set copy publishers checked destination existence
with lstat and then called Node's rename, which replaces the target on
every platform (libuv passes MOVEFILE_REPLACE_EXISTING on Windows). A
file, symlink, or empty directory created between the check and the
rename was silently overwritten, and the identity confirmation could not
recover it because the publication record only proved the staged object
arrived. Claim the destination with mkdir — which fails with EEXIST if
anything occupies the path, so the claim itself is the existence check —
and move the staged children into the claim, restoring the source mode
on it. A failed child move relocates the children back and removes only
the claim. Covered for mono, multi, and simulated Windows, including an
injected concurrent creator at the claim instant.
Restrict backup pruning to directories whose names match the DWS stamp
format (YYYYmmdd-HHMMSS with optional -N suffix) across all 8 installer
surfaces (Go, npm, 4 shell, 2 PowerShell). Unknown directories in
~/.dws/skill-backups are now preserved. Also fixes Windows coverage test
portability and covers the remaining macOS changed-code gap (retire
warning loop in runUpgrade).
A universal Agent whose obsolete private copy cannot be retired installs
nothing there, yet every entry point counted that retirement failure as an
install failure — aborting `npm install`, `dws skill setup`, and the shell
installers even when the canonical store and all links published correctly,
and skipping the skills-state write. Route retirement failures to a separate
warning path across all surfaces (Go upgrade + skill setup, npm, PowerShell,
install.sh, install-skills.sh, install-event.sh, install-devapp.sh).
Also:
- Add a checked-rename fallback for filesystems that reject the atomic
no-replace flag (NFS, FUSE, overlayfs); the no-clobber contract is kept and
the previously unsupported platforms build and work.
- PowerShell multi-mode links only bundle skills, never the shared canonical
store, so third-party/user skills are no longer fanned into every Agent root.
- Prune ~/.dws/skill-backups to the newest 5 on every surface; encode
HOME-relative backup names on PowerShell to preserve origin.
- Add simulated-win32 junction coverage and rewrite the tautological
no-replace test; remove dead code whose tests gave false coverage.
- Soften the overstated Windows ownership-proof comment (NTFS tunneling).
Flip the agent-skill default from mono (single dws/ dir) to multi
(per-product dingtalk-* + dws-shared) across all distribution faces,
and fix the upgrade path so it no longer re-installs mono alongside
multi (mono+multi co-existence bug).
- upgrade: LocateSkillsRoot prefers the zip multi/ tree; multi refresh
removes mono leftovers and stale skills, refreshes the multi cache
- install.sh/ps1/install-skills.sh/npm install.js: multi real-install
(was print-only), default flipped, mono stays opt-in via DWS_SKILL_MODE
- skill setup: non-interactive default multi; full installs now clean
stale dingtalk-*/dws-shared with confirm-preview disclosure, filtered
(-s/-x) installs stay additive
- mutual exclusion is symmetric and includes dws-shared (previously
leaked through the dingtalk- prefix) on all faces
- install.js: guard empty/corrupt multi trees (fall back to mono),
validate SKILL.md on the mono branch, guard cache refreshes
- docs: roadmap (8/30 back-schedule), migration plan, distribution
mechanism, rollout capability, capability completion, architecture
optimization, wukong comparison (archived; line retired)
Co-authored-by: Cursor <cursoragent@cursor.com>