[wan9chi]

Motivation

On Linux and macOS, a task that writes outside the workspace through a relative path with .., like cp -r dist ../site publishing a build next to the repo, fails with ✗ Cache update failed: paths in archives must not have ... fspy reports a relative open as the working directory joined with the path, .. included, so the write is <workspace>/../site/index.html. vt stripped the workspace root before resolving .., so the path passed the check that it's in the workspace and became the output ../site/index.html, which the archive rejects. A file read that way became an input outside the workspace, unlike the same file read through an absolute path.

Changes

Tracked paths have . and .. resolved lexically, as before, but before the workspace root is stripped, so such a path is outside the workspace and dropped like any other. A path that stays inside, like packages/sub-pkg/../shared/dist/output.js, is still packages/shared/dist/output.js. vt_path gets clean_and_strip_path_prefix, and fspy's IpcPath a method of the same name next to strip_path_prefix, which is unchanged. Windows resolves .. before fspy sees the path, so it wasn't affected. A unit test covers the order, and the malformed Windows drive path that the cleaning after the strip used to catch.

E2E case: write_outside_workspace_through_dotdot (synthetic, vtt fs mkdir ../site write ../site/index.html hi, where .. is the harness's folder holding the staged workspace). Both runs fail today; after, the first is cached and the second hits. The first commit runs it on Unix only, since Windows already caches it.

A standalone fix for main. The 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, sits on it and no longer checks for .. itself.

🤖 Generated with Claude Code

---

Note

Medium Risk
Changes how automatic file-access tracking classifies workspace inputs/outputs, which directly affects cache keys and archive contents; behavior is covered by new unit and e2e tests but touches core caching logic.

Overview
On Linux and macOS, cached tasks that write outside the repo via relative paths like ../site (e.g. cp -r dist ../site) no longer fail with Cache update failed: paths in archives must not have ... The second run can cache hit instead.

Tracked path normalization now lexically resolves . and .. before stripping the workspace root, so paths such as <workspace>/../site/index.html are treated as outside the workspace and dropped from inputs/outputs (same as absolute paths outside the repo). In-workspace paths like packages/sub-pkg/../shared/dist/output.js still normalize to packages/shared/dist/output.js.

Adds vt_path::clean_and_strip_path_prefix and IpcPath::clean_and_strip_path_prefix, wired through tracked_workspace_path; the old strip-then-clean() flow is removed. Unit tests cover ordering and the Windows malformed-path case; an e2e fixture asserts a ../site deploy task caches on repeat run.

^{Reviewed by Cursor Bugbot for commit 827bef8. Bugbot is set up for automated code reviews on this repo. Configure here.}

[github-actions]

fspy benchmark

linux

dynamic/launch             change  -0.18%  [ -5.58% ..  +6.45%]  overhead   +57.28%
dynamic/access             change  -1.08%  [ -7.60% ..  +4.95%]  overhead   +19.73%
dynamic/access-relative    change  +0.25%  [ -4.98% ..  +5.64%]  overhead   +67.33%
dynamic/access-contended   change  -2.42%  [-16.19% ..  +9.18%]  overhead    +9.26%
static/launch              change  +1.42%  [ -6.49% ..  +9.24%]  overhead  +183.01%
static/access              change  +0.35%  [ -5.12% .. +15.05%]  overhead +1445.53%
static/access-relative     change  +0.41%  [ -2.19% ..  +2.74%]  overhead +1979.63%
static/access-contended    change  -1.27%  [ -6.48% ..  +3.12%]  overhead +1084.89%

macos

dynamic/launch             change  -0.41%  [ -5.06% ..  +4.72%]  overhead  +237.06%
dynamic/access             change  +0.35%  [ -1.76% ..  +2.91%]  overhead    +3.28%
dynamic/access-relative    change  -0.52%  [ -7.62% ..  +7.73%]  overhead  +267.22%
dynamic/access-contended   change  +1.72%  [ -6.93% ..  +5.93%]  overhead    +0.49%

windows

dynamic/launch             change  -0.48%  [ -6.92% ..  +4.27%]  overhead   +26.97%
dynamic/access             change  +0.00%  [ -1.10% ..  +1.47%]  overhead    +1.48%
dynamic/access-relative    change  +0.17%  [ -1.96% ..  +1.24%]  overhead    +1.27%
dynamic/access-contended   change  +1.26%  [ -9.82% .. +36.22%]  overhead    +1.74%