fix(devkit): scrub git repo-location env vars in spawned processes

[crs48]

Problem

The .husky/pre-commit final step pnpm vitest run --changed HEAD --passWithNoTests failed falsely whenever the changed-file set pulled in packages/devkit tests (bridge.test.ts, dev-loop.test.ts, git.test.ts). Those tests create real temp git repos and run git worktree add, which died with:

fatal: .git/index: index file open failed: Not a directory

git commit exports GIT_INDEX_FILE (and related repo-location vars) into the hook environment; NodeCommandRunner spread process.env into every child, so the tests' spawned git processes were silently redirected at the outer repo instead of their temp-repo cwd. The same tests pass outside the hook.

Fix

• packages/devkit/src/command-runner.ts (the robust fix): NodeCommandRunner drops the git repo-location vars (GIT_DIR, GIT_WORK_TREE, GIT_INDEX_FILE, GIT_OBJECT_DIRECTORY, GIT_ALTERNATE_OBJECT_DIRECTORIES, GIT_COMMON_DIR, GIT_PREFIX) from the inherited env before spawning. An explicit value via options.env still wins. This covers both the Git class and the tests' direct runner.run('git', …) setup calls, and protects any devkit consumer that runs inside a hook.
• .husky/pre-commit: the vitest step runs under env -u GIT_INDEX_FILE -u GIT_DIR -u GIT_WORK_TREE as defense for any other suite that spawns git.
• New regression test in command-runner.test.ts pinning the scrub + override-wins behavior.
• Changeset: @xnetjs/devkit patch.

Verification

• Reproduced first: with GIT_INDEX_FILE/GIT_DIR pointed at the repo, all 5 git.test.ts tests failed with the reported error; after the fix, the full devkit suite (54 tests) passes under the same polluted env.
• End-to-end: the commit on this branch ran the pre-commit hook itself with devkit in the changed set — vitest ran git.test.ts (incl. worktree add) inside the real hook environment and passed.
• Full suite green on push (938 files / 10,212 tests via the pre-push hook).

🤖 Generated with Claude Code

[github-actions]

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[github-actions]

Preview: https://xnet.fyi/pr/400/app/

[crs48]

Closing as superseded — and flagging that merging this branch would regress main.

The fix landed independently in packages/devkit/src/command-runner.ts on main, in a strictly better form:

• 8 scrubbed vars (this branch has 7 — it is missing GIT_NAMESPACE).
• Scrubbed only for command === 'git', rather than for every spawned command.
• options.env is spread last, so an explicit override still wins.

The hazard is that this branch predates exploration 0391. Its command-runner.ts contains no NodeLineRunner, LineRunner, StreamRunOptions, or FakeLineRunner — the streaming agent seam that Claude Code's --output-format stream-json path depends on:

$ git diff origin/main pr400 -- packages/devkit/src/command-runner.ts
# ~150 deleted lines, covering the whole 0391 streaming seam

GitHub reports this PR as CONFLICTING, which is the only reason that has not already happened. Do not reopen and resolve conflicts in favour of this branch — it would silently delete the seam.

Rationale and full triage: docs/explorations/0410_[_]_OPEN_PR_TRIAGE_AND_THE_STRANDED_BRANCH_PROBLEM.md.