process: boot from a deleted cwd, throw node's ENOENT from process.cwd() (+4 tests) - #34843
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cirospaciari wants to merge 3 commits into
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process: boot from a deleted cwd, throw node's ENOENT from process.cwd() (+4 tests)#34843cirospaciari wants to merge 3 commits into
cirospaciari wants to merge 3 commits into
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A getcwd failure at startup aborted every entry point with a generic
ENOENT. Node falls back to the executable's directory
(Environment::GetCwd in env.cc) and lets process.cwd() surface the
error later.
- add bun_core::getcwd_or_exe_dir and use it for the synthetic entry
paths (-e/-p, stdin, cron, node-emulation eval and relative scripts,
feedback) and for the parsed startup cwd of runtime commands only;
install/test/build keep the hard error so they never act on a tree
found above the executable
- an absolute --cwd no longer needs a live cwd; a relative one still
errors; the stored cwd is the post-chdir physical path so
process.cwd(), path.resolve, and the resolver agree
- route a bare --interactive to the REPL like node's --interactive
Enables test-cwd-enoent{,-preload,-repl}.js (verbatim from Node
v26.3.0).
process.cwd() returned the resolver's cached top_level_dir, so it kept
returning a stale path after the directory was rmdir'ed. Node re-runs
uv_cwd on every cache miss and clears its cache on chdir
(lib/internal/bootstrap/switches/does_own_process_state.js).
- Bun__Process__getCwd now does a real getcwd and on failure throws
Node's uv_cwd UVException (message, code, errno, syscall verified
byte-identical against node v26.3.0)
- Process_functionChdir clears the cached cwd instead of repopulating
it, so the next process.cwd() re-queries the OS
- WriteStream's internal $fastPath no longer path.resolve()s its
discarded path, so child_process spawn keeps working from a deleted
cwd (its stdin wiring constructs WriteStream(""))
- drop the now-unused node::path get_cwd alias
The hot path is unchanged: the cached JSString still serves repeated
process.cwd() calls; only the first call after startup or chdir pays
the syscall.
Enables test-cwd-enoent-improved-message.js (verbatim from Node
v26.3.0).
Collaborator
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Updated 1:42 PM PT - Jul 20th, 2026
❌ @autofix-ci[bot], your commit 12c23e7 has 1 failures in 🧪 To try this PR locally: bunx bun-pr 34843That installs a local version of the PR into your bun-34843 --bun |
Contributor
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Found 1 issue this PR may fix:
🤖 Generated with Claude Code |
Member
Author
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Folded into #34660 (branch merged) as part of PR consolidation — same commits and tests, fewer PRs. |
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Bun could not start from a deleted working directory, and
process.cwd()served a cached value forever after the directory vanished. Node boots fine and throws its uv_cwd ENOENT on the call. Two signed commits.Startup from a deleted cwd
Root cause:
Arguments.parseand every synthetic entry-path builder (-e, stdin, cron, node-emulation) didgetcwd(...)?→ hard abort. Node'sEnvironment::GetCwdfalls back to dirname(exec_path). Bun now does the same via a bounds-checkedgetcwd_or_exe_dir— deliberately restricted to runtime commands (Auto|Run|RunAsNode):bun install/test/buildfrom a deleted cwd keep the hard error, because an early iteration of this fix silently raninstallagainst the repo found above the executable — caught by re-driving the CLI, and exactly the failure a fallback must not create.--interactive(bare) now routes to the REPL as node does; with a script, the script wins (node's behavior, checked on the binary).process.cwd()after the cwd vanishesByte-identical to node v26.3.0: message,
code: 'ENOENT',errno: -2,syscall: 'uv_cwd', including the "was likely removed without changing the working directory" hint. Root cause was two caches: the C++m_cachedCwdwas repopulated on chdir where node clears it, and the Rust side read the resolver'stop_level_dirinstead of the OS.Perf, measured rather than assumed: hot path unchanged — 2M cached calls: 8.1-8.7ms control vs 8.8-8.9ms fixed (~4.4ns/call both). Only the first call after startup/chdir pays one syscall, node's exact cost model.
Ride-along fix this exposed:
writableFromFileSinkbuilt aWriteStream("")whose ctorpath.resolve("")d — sochild_processspawn from a deleted cwd threw. The internal fast path now skips resolution of a path it discards two lines later.Deliberately skipped: warning printer through
process.stderrReported, not attempted: (a) bun's default warning printer is the native console inspector and there is no in-tree "format to string" hook, so formatting cannot be preserved through
process.stderr.write; (b) node's default handler is a bootstrap-registered'warning'listener that prints even when user listeners exist — flipping bun to that silently changes stderr for every program withexpectWarning-style listeners. Needs its own PR with node's format adopted deliberately.Verification
4 tests byte-identical to upstream, 3× green, failing on unfixed bun, 12 tampers all non-zero. Adversarial probes:
bun install/add/testfrom deleted cwd still exit 1; relative--cwdfrom deleted cwd still errors;--cwd <symlink>now yields consistent physical paths; repeated chdir→rmdir→cwd() throws every iteration; cache identity preserved.Regressions: fs 606/0, path 122/0, fs+path+child_process+run-eval 869 pass / 1 pre-existing network fail; process 209 pass with the control binary failing the same 3 plus 2 more;
bun run rust:check-all10/10 targets.Known limitations (flag errored before, so these are strict improvements):
--interactive -eevaluates and exits where node stays in the REPL;-iis not aliased (bun's-i=--install=fallback).