[wan9chi]

Motivation

A task that lists a folder holding its own outputs pins those outputs as entries of the listing. TypeScript 7's tsc with no include, for example, lists the package root that holds its lib output folder. A clean checkout lacks them, so it misses. Today only an entry named dist is spared, by a hard-coded skip.

Changes

When a listing is fingerprinted, the entries the task can rebuild are left out and their names recorded with the listing: a file or symlink it wrote, or a rebuildable folder. The listing becomes PathFingerprint::Folder(Option<DirListing>), with DirListing { entries, ignored_entries }, so only a listing can carry ignored names. Validation drops the same names from the current listing before comparing, so they may be missing or present. Any other entry that differs still misses and is named. On file systems that don't report entry types, an entry's kind is looked up with fstatat, so listings and the folder climb agree. The cache schema version is bumped.

E2E cases: list_folder_holding_output (synthetic; an unrelated new file still misses) and typescript_lib_out_dir (TypeScript 7, outDir: "lib").

Part of a stack that lets automatic tracking cache tasks which read their own outputs and list the folders holding them, so they also hit on a clean checkout.

🤖 Generated with Claude Code

---

Note

Medium Risk
Changes post-run fingerprint semantics and invalidates existing cache entries (schema v21), which affects cache hit/miss correctness for any task that lists directories containing its outputs.

Overview
When a cached task lists a parent folder that also contains its outputs, those rebuildable files and output-only subfolders no longer appear in the stored directory listing. Their names are kept in ignored_entries, and cache validation strips the same names from the live listing before comparing, so a clean checkout without lib, gen/, etc. can still cache hit and replay restores outputs.

PathFingerprint::Folder now wraps DirListing { entries, ignored_entries } instead of a plain entry map; CACHE_SCHEMA_VERSION is bumped to 21. Rebuildable gains is_rebuildable_entry (and related helpers) so listing fingerprinting matches the existing “output-only folder” logic. On Unix, directory entries without a reported type are classified via fstatat, aligning listings with rebuildable-folder detection.

New e2e fixtures cover synthetic “list package root after writing gen/” and tsc with outDir: lib; typescript_incremental is no longer Unix-only now that listing behavior is generalized.

^{Reviewed by Cursor Bugbot for commit c7a32cb. Bugbot is set up for automated code reviews on this repo. Configure here.}

[github-actions]

fspy benchmark

linux

dynamic/launch             change  +0.76%  [ -3.85% ..  +7.08%]  overhead   +60.11%
dynamic/access             change  +0.00%  [ -8.27% ..  +7.74%]  overhead   +25.65%
dynamic/access-relative    change  +0.54%  [ -8.83% ..  +7.07%]  overhead   +75.63%
dynamic/access-contended   change  -0.15%  [-10.34% .. +10.77%]  overhead   +13.64%
static/launch              change  +0.60%  [ -5.48% ..  +6.93%]  overhead  +184.25%
static/access              change  +0.31%  [ -5.70% ..  +8.67%]  overhead +1394.89%
static/access-relative     change  -1.36%  [-14.55% ..  +2.57%]  overhead +1840.74%
static/access-contended    change  -0.20%  [ -4.31% ..  +4.45%]  overhead +1343.91%

macos

dynamic/launch             change  -1.39%  [ -6.28% ..  +3.03%]  overhead  +228.14%
dynamic/access             change  -1.54%  [-55.33% .. +86.18%]  overhead    +0.37%
dynamic/access-relative    change  +0.95%  [ -5.39% .. +30.70%]  overhead  +251.15%
dynamic/access-contended   change  -1.33%  [ -9.25% ..  +9.87%]  overhead    +0.51%

windows

dynamic/launch             change  -0.09%  [ -2.21% ..  +2.55%]  overhead   +26.31%
dynamic/access             change  +0.00%  [ -0.64% ..  +0.85%]  overhead    +1.72%
dynamic/access-relative    change  +0.00%  [ -1.89% ..  +2.09%]  overhead    +2.06%
dynamic/access-contended   change  -0.40%  [ -6.17% ..  +1.20%]  overhead    +2.24%

[cursor]

Cursor Bugbot has reviewed your changes using high effort and found 1 potential issue.

^{❌ Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

^{Reviewed by Cursor Bugbot for commit c7a32cb. Configure here.}