watch: report a failed reload exec as an error instead of a panic by robobun · Pull Request #39975 · oven-sh/bun

robobun · 2026-08-21T15:37:53Z

Problem

A --watch reload crashes with panic: Unexpected error while reloading: errno 2 plus a crash report when the executable the session was started from is gone or is not runnable any more (Sentry BUN-4NGV). Repro: copy bun, start --watch from the copy, rm the copy, save a file.
The cause is reload_process in src/bun_core/util.rs. When execve returns, the may_return == false path (every --watch caller) calls panic!. This is an OS error from the user's environment, not an invariant.
On Linux the same panic also hits an in-place upgrade. Once the running binary is unlinked, /proc/self/exe reads <path> (deleted), and self_exe_path() is first computed at reload time, so execve fails with ENOENT even though the new binary sits at <path>.

Fix

On a failed execve, print error: Failed to reload "<path>": ENOENT: No such file or directory (execve) and exit with code 1. The crash handler's auto-restart (may_return == true) prints the same line and returns, as before. Every errno takes this route (EACCES, ETXTBSY, ENOMEM, ...).
Exiting is correct because on_before_reload_process_posix has already reset the signal dispositions, so the old image cannot safely keep running. The callers that follow the call with unreachable!() are unchanged: the function still never returns to them.
Linux and Android: when the first exec fails with ENOENT and the path ends in (deleted), exec the path without the suffix. An upgraded bun now reloads into the new binary. The error names the path that was tried last.
Verified: test/cli/watch/watch.test.ts, two new tests (removed executable, replaced executable). Both fail on the released bun (panic, and the process dies before the second run). Also ran test/cli/hot/watch.test.ts and test/cli/watch/watcher-trace.test.ts.

Background

bun --watch does not reload modules in place. On a file change the watcher thread calls reload_process, which execves the same executable with the same argv and env. The new process starts from scratch.
on_before_reload_process_posix (src/jsc/bindings/c-bindings.cpp) runs right before the exec. It clears CLOEXEC on stdio, marks the other fds CLOEXEC and resets caught signal handlers to their defaults.
reload_process lives in bun_core, which cannot depend on bun_errno. The errno name and text come from the ErrnoNames link interface and coreutils_error_map, the same tables Output::err uses.

Notes

Fix --watch reload panic when the executable has been deleted or replaced #31691 fixed the same crash in June. It is stale and conflicts with main now. This change differs from it in two points: every errno exits instead of a fixed list, and the message has the same shape as other syscall errors.
The message was checked by hand on the watcher thread path (no kill-signal listeners, the default) and on the JS thread path (a SIGTERM listener registered). With colors on, the screen is cleared first and the error is the only line on the fresh screen.
macOS has no (deleted) suffix. _NSGetExecutablePath returns the start path, so a replaced binary already reloads there. The replaced-binary test covers that behavior on both platforms and the retry on Linux.
self_exe_path() still uses .expect("unreachable"). It only fails when /proc is not mounted on Linux. Not changed here.
The new tests copy the executable into the temp dir, so they take about 0.6 s and 1.4 s with an 800 MB debug build here. Release binaries are much smaller. 30 reruns passed.
cargo check -p bun_core passes for linux, musl, android, darwin, freebsd and windows targets. clippy and rustfmt are clean.

no test proof · iteration 0 · Platform-specific test(s) that do not run on this machine. Deferring to CI, which covers all platforms: test/cli/watch/watch.test.ts

coderabbitai · 2026-08-21T15:38:01Z

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src/bun_core/util.rs
test/cli/watch/watch.test.ts

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Walkthrough

POSIX process reload now captures executable paths and errno values when execve fails. Linux and Android retry paths ending in (deleted) after ENOENT. Failure reporting includes path and errno details, then returns or exits based on may_return. Watch-mode tests cover executable removal and replacement.

Changes

Process reload

Layer / File(s)	Summary
Reload failure handling `src/bun_core/util.rs`	The POSIX reload path captures the attempted path and errno. On Linux and Android, it retries paths ending in `(deleted)` after ENOENT. Failure reporting includes the path and recognized errno details, or the numeric errno. The function returns or exits according to `may_return`.
Watch-mode reload tests `test/cli/watch/watch.test.ts`	Tests start watch mode from a copied executable. They check the reported ENOENT and exit code when the executable is removed, and check that watch mode continues after atomic executable replacement.

Suggested reviewers: cirospaciari, jarred-sumner

Priority: ⬇️ Low

Merge Risk: ⚪ Minimal · up to d41b2

Failed watch reloads now report the executable path and OS error instead of panicking, while executable replacement supports successful reloads. No actionable merge-blocking risk remains; platform runtime behavior was not independently tested.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title is concise, specific, and accurately describes the primary change: reporting failed reload exec calls as errors instead of panicking.
Description check	✅ Passed	The description clearly explains the problem, fix, platform-specific behavior, testing, and verification results. It does not use the exact template headings, but it provides the required information …
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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robobun · 2026-08-21T15:38:46Z

Status: reproduced on the released bun (1.4.0 canary, Linux) with the steps below. Fixed and tested in this PR. The PR is in draft while the design gets its review.

cp "$(which bun)" ./bun-copy
printf 'console.log("start"); setInterval(() => {}, 1000)\n' > app.js
./bun-copy --watch app.js &
sleep 1; rm ./bun-copy; echo '// edit' >> app.js
# before: panic: Unexpected error while reloading: errno 2, plus a crash report
# after:  error: Failed to reload "/.../bun-copy": ENOENT: No such file or directory (execve), exit code 1

The same steps with cp + mv over the copy instead of rm (an in-place upgrade) also panicked on Linux before this change. They now reload into the new binary. That retry comes from #31691, an earlier PR for the same crash. #31691 is closed in favor of this PR.

claude

LGTM — replaces a user-reachable panic with a proper error+exit, and the Linux (deleted) retry is a nice fix for the upgrade case.

What was reviewed:

reload_process still never returns to may_return=false callers (Global::exit is -> !); the crash-handler may_return=true path keeps its print-and-return behavior.
Checked the ZBox::from_bytes(path).as_zstr() temporary lifetime in the retry arm — the ZBox outlives the exec call.
Test 1's assertion on the bare ${exe} path holds on both Linux (retry strips the suffix, second ENOENT reports the stripped path) and macOS (tempDir already realpath's, so _NSGetExecutablePath+realpath matches exe).
Tests reuse the file's stdoutWaiter/watchee conventions, drain stderr concurrently, and keep the copied exe outside the watched dir.

Extended reasoning...

Overview

Changes reload_process in src/bun_core/util.rs so that a failed execve on the POSIX --watch reload path prints a formatted error (error: Failed to reload "<path>": <ERRNO>: <msg> (execve)) and exits with code 1 instead of panicking. Adds a Linux/Android-only retry: when /proc/self/exe resolves to <path> (deleted) and the first exec fails with ENOENT, exec <path> so an in-place bun upgrade reloads into the new binary. A new #[cold] helper report_reload_failure formats the errno via the existing ErrnoNames link interface and coreutils_error_map (bun_core cannot depend on bun_errno). Two new tests in test/cli/watch/watch.test.ts cover the removed-executable and replaced-executable cases.

Security risks

None. The change narrows behavior on an already-failing path (execve returned) from panic to error+exit. The (deleted) retry only execs a suffix-stripped copy of the kernel-reported /proc/self/exe target — no user-controlled input is involved.

Level of scrutiny

Medium. reload_process is process-lifecycle code called from the watcher thread, the JS thread, and the crash handler, but the diff is small and localized to the failure path after execve returns. I verified: Global::exit(1) is -> !, so the may_return=false callers in hot_reloader.rs, VirtualMachine.rs, and node_process.rs still never see control return; the may_return=true crash-handler caller now gets the same message via report_reload_failure and returns, matching the old pretty_errorln+return; the exec closure's borrows of newargv/envp are live across both calls; the temporary ZBox in the retry arm lives for the full expression; and on non-Linux unix the cfg-gated shadowing block is skipped so (failed_path, errno) from the first exec flows straight to the report.

Other factors

The tests follow the existing patterns in the file closely — stdoutWaiter, the shared watchee + afterEach SIGKILL cleanup, tempDir with using, and stderr drained via .text() started before the blocking stdout read. The copied executable lives outside the watched app/ subdir so removing/replacing it does not itself trigger a reload. I traced the first test's expected message on both platforms: on Linux the retry reports the suffix-stripped path (matching exe), and on macOS tempDir is built on realpathSync.native(os.tmpdir()) so self_exe_path()'s realpath of _NSGetExecutablePath matches exe. The PR description documents USE_SYSTEM_BUN=1 failure, 30 reruns, and cross-target cargo check. This directly implements the repo guidance that user-reachable failures are errors, not panics.

robobun · 2026-08-21T16:04:07Z

#31691 is closed in favor of this PR. Two notes from that PR's history, in case they are useful here:

Its reviews asked for exactly what this diff already does: report the path that the final execve used (here failed_path), and print the same message on the may_return path. Nothing else came up in three rounds.
spawnWatchFromCopiedExe copies the executable once per test. The debug build is about 1 GB, so Fix --watch reload panic when the executable has been deleted or replaced #31691 used linkSync first and fell back to copyFileSync only across filesystems. Optional, it only affects test time on debug and ASAN lanes.

reload_process re-execs the executable the process was started from. When that path is gone or not runnable any more (bun was removed or replaced while --watch ran, EACCES, ETXTBSY), execve fails and the process panicked with "Unexpected error while reloading: errno 2" and printed a crash report. Print the executable path and the errno instead and exit with code 1. The crash handler's auto-restart path keeps returning, with the same message. On Linux, /proc/self/exe reads "<path> (deleted)" once the running binary is unlinked, which is what an in-place upgrade does. When the first exec fails with ENOENT and the path carries that suffix, exec <path> so the reload lands on the replacement.

github-actions · 2026-09-30T19:50:02Z

+/// Port of `bun.reloadProcess`. On failure the executable path and errno are printed, then
+/// `may_return == true` (the crash handler's auto-restart) returns and `false` exits with 1: the
+/// old image cannot safely carry on once `on_before_reload_process_posix` has reset the signal
+/// dispositions, and an executable that was removed or made unrunnable under a running `--watch`
+/// is not a bug, so it is not a panic either.


If you need a paragraph-long comment to justify why the workaround is OK, the code is wrong — fix the code

github-actions · 2026-09-30T19:50:02Z

+        // Once the running binary is unlinked, /proc/self/exe reads "<path> (deleted)". After an
+        // in-place replacement (`bun upgrade`, a reinstall) the new binary is at <path>: exec it.


If you need a paragraph-long comment to justify why the workaround is OK, the code is wrong — fix the code

robobun · 2026-09-30T19:50:07Z

^{Updated 1:15 PM PT - Sep 30th, 2026}

❌ @robobun, your commit d41b244 has 1 failures in Build #121947 (All Failures):

test/js/bun/spawn/spawn.test.ts - code 1: stdout reader of an unref'd child and process lifetime > an idle reader stopped at the highwater … on 🐧 13 x64-asan

🧪 To try this PR locally:

bunx bun-pr 39975

That installs a local version of the PR into your bun-39975 executable, so you can run:

bun-39975 --bun

robobun · 2026-09-30T19:54:25Z

Moved this PR back to draft. Three things are open:

The two comment findings above are valid. The doc comment on reload_process is too long. The (deleted) retry needs a comment to explain it, which points at a workaround. The next push shortens the first and re-checks the second. One option is to resolve the executable path when watch mode starts, so that the path never carries the suffix.
The design did not get a review before the code was written, and the body has no Downsides section. Both come with the next push.
Fix --watch reload panic when the executable has been deleted or replaced #31691 was an earlier PR for the same crash with the same approach, and the (deleted) retry here comes from it. It is closed in favor of this PR.

Edit: the first version of this comment said that #31691 is still open. That was wrong. It closed on Aug 21.

robobun · 2026-09-30T19:56:29Z

Rebased on main (bf42a52, force pushed). The old head was 22aff80, the new head is d41b244.

One conflict, in the import block of test/cli/watch/watch.test.ts. Main added isMacOS, readFileSync, readlinkSync, realpathSync and symlinkSync there. This PR adds copyFileSync, renameSync and basename. The block now has both sets.

No source line of the diff changed. src/bun_core/util.rs applies as it was.

Checked on Linux x64 with a debug (ASAN) build:

On main, the two new tests fail. The first gets a crash report in place of the error. In the second, the process dies at the reload.
With the change, both pass, and watch.test.ts passes as a whole.

The build with the change also had the other branches that I rebased in the same pass. CI is the check for this branch alone.

claude

Nothing blocking. The comments below are optional suggestions. There is no need to push a fix for them before merging.

claude · 2026-09-30T20:13:39Z

+function spawnWatchFromCopiedExe(dir: string) {
+  const exe = join(dir, basename(bunExe()));
+  copyFileSync(bunExe(), exe);


🟡 (optional) CI runs of this file get several extra seconds and gigabytes of temp-disk traffic per run, and debug/ASAN lanes get scrutinized or time out. spawnWatchFromCopiedExe at test/cli/watch/watch.test.ts:280 copies the whole bunExe() into tempDir on every call, and the second test copies it again at line 328, so one file run writes three full copies of the debug binary serially. The PR itself measures 0.6 s and 1.4 s with an 800 MB build on a dev box, already past the ~1 s/test budget, and ASAN binaries are larger. Fix: keep one copy per file (beforeAll into a shared tempDir, hard-link or rename for the replacement case) and run the two cases with test.concurrent, or drop to a tiny fixture executable.

Why this was flagged

Both new tests are plain it (test/cli/watch/watch.test.ts:302 and 323), so they run serially after the rest of the file. Each calls spawnWatchFromCopiedExe (line 278-283), which does copyFileSync(bunExe(), exe) into a fresh tempDir; the replacement test then does a second copyFileSync at line 328 while the running process still pins the unlinked first copy, so two full images sit in the temp filesystem at once. bunExe() lives in the build dir, not in tmp, so copy_file_range/reflink cannot short-circuit a cross-filesystem copy on Linux; only macOS clonefile is cheap. The PR text reports 0.6 s and 1.4 s locally for an 800 MB debug build and the robobun footer says the tests were not executed here, so the CI cost on the debug+ASAN lane (larger binary, 10-100x slower startup) is unmeasured. The base branch has no test in this file that copies the executable. Repo review instructions flag a new test past ~1 s, and a file staying serial without reason, as changes-requested. Remedy: one shared copy per file with test.concurrent, or a hard link/rename instead of a second copy.

Verification: nit — triggered on every non-Windows run of this file. spawnWatchFromCopiedExe at /home/claude/bun/test/cli/watch/watch.test.ts:280 does copyFileSync(bunExe(), exe) and is called once by each of the two new tests (lines 304 and 325), and the replacement test does a third full copy at line 328 — three full images of the debug binary written serially per file run.

claude · 2026-09-30T20:13:39Z

+  await Bun.write(join(String(dir), "app", "entry.js"), ENTRY_SECOND);
+
+  expect(await stderr).toContain(`error: Failed to reload "${exe}": ENOENT: No such file or directory (execve)`);
+  expect(await stderr).not.toContain("Bun has crashed");


🟡 nit (optional): CLAUDE.md forbids asserting the absence of crash text in test output, and this line does exactly that. test/cli/watch/watch.test.ts:313 asserts not.toContain("Bun has crashed"), which root CLAUDE.md line 100 says never to write because such assertions never fail in CI. The exact-message check on line 312 and exitCode 1 on line 314 already fail on a panic. Fix: delete the line 313 assertion and keep the positive message and exit-code assertions as the sole checks. [also at: test/cli/watch/watch.test.ts:315 - nit: this assertion breaks the repo test rule against checking for the absence of crash text and adds nothing the other two assertions do not already prove.]

Why this was flagged

The root CLAUDE.md (line 100) states: NEVER write tests that check for no "panic" or "uncaught exception" or similar in the test output, because these tests will never fail in CI. test/cli/watch/watch.test.ts:313 adds expect(await stderr).not.toContain("Bun has crashed"). The assertion is vacuous relative to line 312, which asserts the exact error: Failed to reload "...": ENOENT: No such file or directory (execve) line, and line 314, which asserts exit code 1 (a panic path exits via the crash handler with a different status). On the base branch no such assertion exists; after merge a maintainer inherits a convention violation with no added coverage.

Verification: nit. Triggering condition: always. test/cli/watch/watch.test.ts:313 reads expect(await stderr).not.toContain("Bun has crashed");. Root CLAUDE.md:100 states: NEVER write tests that check for no "panic" or "uncaught exception" or similar in the test output. These tests will never fail in CI. The assertion is also redundant: lines 312 and 314 already fail on a regression to the panic.

claude · 2026-09-30T20:13:39Z

+
        // we must clone selfExePath in case argv[0] was not an absolute path
-        let exec_path = self_exe_path().expect("unreachable").as_ptr();
+        let exec_path = self_exe_path().expect("unreachable");


🟣 pre-existing, not blocking: pre-existing: a --watch user on Linux whose process cannot read /proc/self/exe still gets a panic and crash report on reload, not the new error line. src/bun_core/util.rs:4386 keeps self_exe_path().expect("unreachable"), so a failed current_exe() (no /proc mounted, e.g. a bwrap or chroot sandbox) panics before report_reload_failure is reached. Fix: treat a failed self_exe_path() like a failed execve on every reload path — print the same Failed to reload error with the cause and return or exit(1) per may_return — so no user-environment condition on the reload path panics.
A small fix can ride a push you are already making; otherwise a short reply is enough.

Why this was flagged

Trigger: bun --watch app.js running on Linux where /proc is not mounted (sandboxes started without a proc mount, minimal chroots); a file change makes hot_reloader.rs:576 or hot_reloader.rs:641 call reload_process(_, false). At src/bun_core/util.rs:2705 std::env::current_exe() fails because readlink(/proc/self/exe) fails, so self_exe_path() returns Err and src/bun_core/util.rs:4386 .expect("unreachable") panics. That panic happens after on_before_reload_process_posix (util.rs:4354) has already reset signal dispositions, and it goes through the crash handler exactly as the base branch's panic!("Unexpected error while reloading…") did, producing a crash report for an environment condition. The PR's stated purpose is to make a reload that cannot exec a plain error plus exit 1; this sibling failure on the same path is left as it was on the base branch. The author's note says this is intentionally unchanged; it is the only remaining user-reachable panic on the unix reload path.

Verification: src/bun_core/util.rs:2705 std::env::current_exe() is readlink("/proc/self/exe") on Linux, so no /proc yields Err. src/bun_core/util.rs:4386 is let exec_path = self_exe_path().expect("unreachable");, which runs before the new report_reload_failure at 4397, so the failure panics instead of printing the Failed to reload error. The base branch panics identically here.

robobun · 2026-09-30T20:23:05Z

The three review findings above are valid. They go into the next push, together with the two comment findings. Nothing is pushed for them yet.

not.toContain("Bun has crashed"): the next push removes it. The exact message and the exit code already fail on a panic.
Executable copies: the next push hard-links the executable. It copies it at most once per file run, and only when the temp directory is on another filesystem.
self_exe_path().expect("unreachable"): this is part of the design re-check. The next push handles a failed lookup like a failed exec, or the reply on that thread says why not.

… and CLI (#46021) ### What does this PR do? Hardening. This collects the open pull requests that fix a crash in Bun into one change, and fixes about 20 more crashes that had no pull request. "Crash" here means a segfault, a Rust panic, an abort, a failed assertion, memory corruption that a sanitizer reports, a native stack overflow, or an exception that ends the process and that the program can't catch. With this PR those cases throw a normal error, print a normal CLI error and exit 1, or just work. 306 pull requests are included: 227 whole, and 79 cut down to the crash fix where the rest was a refactor, a feature or a behavior change. Each one was checked against current `main` first. 45 more turned out to be fixed already, and 17 were duplicates. The full list is at the bottom. #### Crashes you could hit in normal use - **`bun build` with macros and a `.env` file crashed at random.** In a repro with many macro modules, more than a third of the builds crashed. Now 3,000 of 3,000 produce the right bundle. (#45960) - **`bun run` and `bunx` aborted if a signal arrived while the child was being spawned.** (#38926, #45965) - **`bun build --compile ./index.js ./public/*` panicked** if an embedded file's name wasn't valid UTF-8. - **A truncated or corrupted compiled executable** died with SIGBUS or a panic at startup. It now prints an error. (#31787, #38251, #41360) - **Dev server:** several `Option::unwrap()` panics after a failed or deleted import (#38046, #44744, #44746), a segfault when an `onLoad` plugin throws while another bundle is queued, a request that hung and then panicked with `bundle active`, and `server.stop()` that never resolved after a client aborted a waiting request. - **`Bun.serve`:** `server.fetch(url, { headers: new Headers() })` followed by a GC segfaulted (#40888). Routes were used after free after `server.reload()` with `tls.serverName` (#38636). - **`text()` and `json()` on a stream of string chunks** could abort the process, a regression in 1.4.0. (#44269) - **`Bun.Transpiler` with `exports.eliminate` or `exports.replace`** aborted on `export default 1` and on most re-export clauses. (#44137) - **A decorated `declare` field in a class expression** with `experimentalDecorators` panicked. (#38095) - **YAML and JSON5 files with a key that isn't a string** panicked with `--no-bundle` and in `Bun.Transpiler`. (#41827) - **`Bun.FileSystemRouter`:** reading `.params` segfaulted when a rejected route candidate left its parameters behind. (#39290, #39291) - **Native addons that call `uv_async_*`, `uv_timer_*`, `uv_idle_*`, `uv_prepare_*`, `uv_check_*`, `uv_queue_work` or `uv_cwd`** aborted with "unsupported uv function" on Linux and macOS. They're implemented now. (#36609, #39652, #39892) - **`--watch` and `--hot`** panicked when the system was out of inotify instances or file descriptors, or when the reload `exec` failed. They print an error now. (#39629, #39975, #44837) - **Paths longer than the path buffer** panicked in `bun install`, the resolver, the bundler, `--compile`, `tsconfig.json` `paths` and `baseUrl`, `package.json` `main` and `sideEffects`, `bun run --filter`, `bun pm diff`, source maps and snapshots. They're ordinary errors now, or they work. (#36340, #37529, #39104, #39650, #43067) - **A Worker that creates a `ShadowRealm` and imports `node:worker_threads` in it** segfaulted. - **`structuredClone` or `postMessage` of an X25519 key** gave an object that aborted the process when read. (#45624) - **`node:stream` web adapters and `node:http2`** could end the process with an exception that no handler could catch. (#45076, #45975) - **Windows:** a watcher panic in a burst of file changes (#44344), a segfault after the machine resumes from sleep (#33015), crashes in the shell's pipe reader (#39638, #43606), and addons that import from `node.exe` without the delay-load hook (#35618). Most of the rest needs unusual input: strings near the 2 GiB limit, buffers that another thread or a getter resizes or detaches in the middle of a call, `worker.terminate()` at a bad moment, running out of memory or file descriptors, very deep nesting, or hostile arguments to `bun:ffi`, `node:vm` and `bun:sqlite`. #### Behavior changes Things that didn't crash before and behave differently now: - `new` on native functions that aren't constructors throws a `TypeError`, as in Node: `util.types.*`, `buffer.isAscii`, `isUtf8`, `transcode`, `resolveObjectURL`, `bun:jsc` exports, `cc()` symbols. It used to return the call's result. They also stop printing as `[class hostname]`. (#34575) - `` $`cmd` `` throws `ERR_INVALID_ARG_VALUE` if an environment variable's name or value contains a NUL byte. It used to cut the value at the NUL. (#44981) - `cc()` functions throw a `TypeError` for arguments that used to reach C as garbage, and `read.*(ptr, NaN)` throws. (#37989, #38057, #40773) - As PID 1, `bun` exits with 128 + the signal number on Ctrl+C or `docker stop`. (#38877) - A `NODE_MODULE` addon that's already loaded by the main thread throws `ERR_DLOPEN_FAILED` when a live Worker loads it too, as in Node. (#39968) - An exception from a `node:vm` context reaches `uncaughtException` handlers. (#39992) `vm.constants.DONT_CONTEXTIFY` returns the real global proxy. (#34623) - `createPrivateKey` rejects an EC JWK whose private value doesn't match its public point. (#33752) - `@dec static {}` is a syntax error, as in TypeScript and esbuild. (#44883) - `clearTimeout` ignores 0 and negative ids, and timer ids no longer wrap. (#44771) - HEAD for a `Response` whose body is an S3-backed `Blob` reports the length that GET sends. (#44734) - `bun:sqlite` and `node:sqlite`: if `iterate()` left a write unfinished on a connection that has a hook, a user function or an authorizer, the write is finished on the connection's next call instead of during garbage collection. If the database is gone too, it's rolled back. - `bun test --bail` runs exit listeners and closes SQLite databases. (#39010) - Dev server: a request for a client script waits while a bundle is in flight (#42733), query strings reach framework routes (#33232), and a request gets a 500 instead of hanging when plugins fail (#36812). #### File formats - `.jsc` bytecode files get a 24-byte footer so they can be verified before decoding. Files from an older Bun are ignored and the source is parsed instead. (#39396) - `node:vm` `cachedData` gets an 8-byte checksum. A blob from an older Bun is rejected, which the API allows. (#32839) - The built-in modules section of a compiled executable changes from format 1 to 2 and carries an engine stamp. (#44907) #### Performance Measured in instructions per operation on release builds of this branch and its base, with an A/A run for the noise floor (0.0 to 0.2 %). No change: `Bun.serve`, `node:http`, WebSocket echo and publish, `bun build` of 3,807 modules, `bun run` with 2,000 imports, `readdir` / `Glob` / `fs.cp` over 23,689 entries, startup and RSS. The binary grows by 176 KB (0.17 %). | Faster | Instructions | | --- | --- | | WebSocket echo of a 1 MB non-ASCII text message | −72 % | | `Bun.inspect` of a large non-ASCII string | −39 % | | `Bun.markdown.html` on large non-ASCII input | −33 % | | `` $`cmd` `` with 300 environment variables | −6 % | | `fs.readSync` | −5 % | | `TextEncoder.encodeInto`, short ASCII strings | −4 % | | async `crypto.pbkdf2`, 16-byte inputs | −17 % | | Slower | Instructions | Why | | --- | --- | --- | | `cc()` calls | +5 to +51 per call | Argument count and type checks, and a check for `close()` (#37989, #38057, #43802, #44921). `dlopen()` calls don't change | | `process.env.X = v` | 38 → 593 per write | Writes aren't cached. Reads don't change (#38871) | | async `crypto.pbkdf2`, inputs of 1 KB or more | +4 to +9 % | Password and salt are copied (#40554) | | `bun build` with an object `--define` used thousands of times | +4.5 % | The object is copied per use (#45969) | #### Not included - Fixes that need a WebKit change: #39967, #42534, #42982, #43764, #43786, #44226. #42185 too: a typed array that has no `ArrayBuffer` yet can't be pinned, so `view.buffer.transfer()` during an async call can still free its bytes. Creating the `ArrayBuffer` up front costs 7 to 12 % on every async `fs` call, so the fix belongs in JSC: an `ArrayBuffer` created while the view is borrowed should start out pinned. - #45442 (`calc()` sums as a flat list): it changes minified output for real stylesheets to survive a `calc()` with 25,000 terms. It deserves its own review. - #40023 (Windows event loop redesign), #29928 (Windows exit path), #40534, #43963, #39571, #42904, #42834, #36355, #43266: refactors or features whose crash is already covered or isn't a crash. - The pull requests marked *(crash fix only)* below should stay open for their other half. ### How did you verify your code works? - **Tests.** Every fix has a test that fails on `main` (a release or an ASAN build) and passes on this branch, except where that isn't practical: code that only runs on Windows or macOS, inputs that need several GB of memory, and a few rare races. Those were checked by hand or by reading. - **Stored repro scripts.** 230 crash repros ran on release and ASAN builds of this branch and of `main`, side by side. Release: 88 no longer crash. ASAN: 106 no longer crash. None crashes that didn't before. What still crashes needs WebKit, is SQLite's own bug, or isn't a crash. The ASAN number is from a later commit than the release number. - **Dev server.** Because one fix makes requests wait, 2,171 generated programs ran random interleavings of edits, build errors, failing plugins, reloads, stops and disconnects with about 120,000 requests. No request hung, was answered twice or got a stale body. `main` hung in 82 of 1,161 programs. This also found the four dev server bugs listed above. - **Path helpers.** 336,000 boundary cases with buffers of exactly the computed size, and 12,003 random calls through 30 JS APIs on an ASAN build, compared with `main`. No sanitizer report, and the results match wherever `main` doesn't panic. - **What worked on 1.4.3 still works.** Reviewers compared behavior with 1.4.3 and took out what changed it: for example an output directory layout change for 9 or more entry points, a `server.reload()` change, and a changed error message for `import("file:///50%deposit.ts")`. - **Not run locally:** the Windows, macOS and FreeBSD code paths. CI compiles and tests them. ### Included pull requests **Bundler, transpiler, CSS, macros** (33) - #33881 bundler: allocate wrapper_ref for CommonJS modules with no non-hoistable statements - #35055 Bun.build plugins: handle filter RegExp flags beyond i/m/v - #37769 bundler: fail the build instead of panicking when the bundle thread cannot create its waker - #37784 bundler: copy inlined env values into the define arena, and give each Bun.build its own env copy *(crash fix only)* - #37858 bundler: fail the build instead of panicking when a plugin answer string cannot be converted - #38046 bun build --server-components: require the bun target and reject directives without a framework *(crash fix only)* - #38095 js_parser: fix panic on decorated declare/abstract fields in class expressions with experimentalDecorators - #38966 bundler: keep deep CSS, export star and composes graphs from overflowing the linker's stack - #38984 bundler: stop an export star ambiguity that loops back into a re-export chain from overflowing the stack - #39113 css: reject stylesheets of 2 GiB or more instead of aborting on an int cast - #39396 bundler: frame .jsc bytecode sidecars and verify them before decoding - #39855 bundler: join the work still on the pools before the bundle is torn down *(crash fix only)* - #41157 dev server: leave out an html link to a cached json module instead of panicking, and mark a new placeholder file stale - #41801 css: decode ill-formed UTF-8 to U+FFFD before tokenizing *(crash fix only)* - #41827 bundler: handle YAML and JSON5 keys that are not strings instead of panicking - #42242 js_parser: compress symbol link chains when following merged declarations - #42387 bundler: check receivers on the Bun.build plugin object and freeze its filters during a build - #42413 Bounds-check the InternalSourceMap window reader - #42657 macros: keep visited values alive so a reused address does not get another value's Expr - #43330 transpiler: do not print an empty `var` for a data file with no named export - #43355 bundler: fix "The memory limit has been exceeded." on large HTML entries - #43658 react-compiler: fix skipped functions and build aborts for dead code in a try body *(crash fix only)* - #44137 js_parser: fix four crashes of exports.eliminate and exports.replace - #44467 js_parser: replace skipped expressions with E::Missing and skip argument checks after a stack overflow - #44662 js_parser: walk binary chains on the heap and check the stack when rewriting decorated #private accesses - #44712 json5: reject sources of 2 GiB or more before parsing instead of aborting on an int cast - #44864 js_parser: walk conditional chains in import()/require() and define keys in a loop - #44883 js_parser: reject a decorator on a class static block, keep decorators out of the body of `declare global` *(crash fix only)* - #45045 Fix a segfault in new Bun.Transpiler(): re-point options.log after the constructor moves its Log - #45604 css: keep a url() in an at-rule prelude as written, and never print the resolved path of a url() *(crash fix only)* - #45748 bundler: put --banner/--footer in the bytecode ESM module record (flags from a parse, entries from JSC) *(crash fix only)* - #45960 macros: give each parse-worker macro VM its own env loader - #45969 js_parser: copy object and array defines per use, and copy the list of a lone JSX spread object *(crash fix only)* **`bun build --compile` and standalone executables** (3) - #31787 Don't crash at startup when a standalone executable's embedded graph is corrupted *(crash fix only)* - #38251 compile: exit with an error instead of SIGBUS when a standalone executable is truncated - #41360 standalone: check every offset in the embedded module graph before reading it **Resolver, module loading, plugins, paths** (25) - #32269 Bun.plugin: validate the namespace without a shared regex - #33183 bun:jsc: filter internal cells out of getProtectedObjects() - #34575 Don't register native functions as their own constructors - #36340 paths: size the thread-local join output buffers to MAX_PATH_BYTES on Windows - #37037 mock.module: reject async factory results that are not objects - #37065 bun:jsc: propagate JSONParse exceptions from samplingProfilerStackTraces - #37529 resolver: don't abort on a package.json sideEffects entry longer than the join buffer - #38179 node:module: throw instead of crashing when module._compile is set to a non-function - #38273 bun test: report a test file or preload the loader cannot resolve instead of exiting; keep the JUnit report valid U… *(crash fix only)* - #38732 paths: compute the common path of 9+ inputs with the same loop as fewer *(crash fix only)* - #39228 paths: strip C:\\ down to the drive root in without_trailing_slash_windows_path *(crash fix only)* - #39650 bun run --filter: stop panicking on workspace paths longer than the path buffer - #40186 resolver: stop deeply nested exports targets from overflowing the stack - #40258 resolver: publish Entry.abs_path through the per-entry mutex - #42183 node:module: reject a _resolveFilename override result that contains a null byte - #42401 node:module: accept any `this` in Module.prototype.require *(crash fix only)* - #42405 Bun.plugin: transpile a copy of typed array onLoad contents - #42414 node:module: end the Module._stat path at the first null byte - #42685 resolver: strip the trailing separator inside bust_dir_cache - #42735 Throw a RangeError instead of aborting when require.resolve paths or Worker preload outgrows its Vector - #43067 Report a path that does not fit a path buffer instead of aborting *(crash fix only)* - #44410 Fix a crash when code from a node:vm context reads require.cache or require.extensions - #44466 Trace the value an object or data module exports from its JSSourceCode - #45044 Bun.plugin: give onLoad's args.path its own bytes - #45117 cjs: do not call an `__esModule` getter during the annotation lookup **Dev server, `bun bake`, routers, `--watch` and `--hot`** (28) - #28793 Stop file watcher thread before Global.exit tears down memory *(crash fix only)* - #32143 bake: fix "Runtime file not found" panic in production builds of custom frameworks - #32443 watcher: don't free the Watcher in the spawn-to-start window *(crash fix only)* - #33232 bake: normalize the HTTP request-target before matching framework routes - #36812 bake: respond 500 and release both RequestContext refs when on_plugins_rejected / OOM drains a deferred framework r… - #37039 bake: report per-file print failures in the dev server instead of serving empty modules - #37276 hot_reloader: take entries_mutex for watcher-thread directory cache probes - #37444 bake: unregister Bake::SourceProvider from the source map table when it is destroyed - #39290 FileSystemRouter: match / against a root-level optional catch-all route *(crash fix only)* - #39291 FileSystemRouter: order dynamic routes by per-segment precedence like Next.js *(crash fix only)* - #39629 watch: report a failed watcher init as an error instead of a crash - #41185 bake: check for exceptions in the production build's module loader hooks and helpers - #41340 bake: skip the directory watch when the directory cannot be opened - #41617 Decide a directory watch event from the watchlist, not from the resolver's cached listing *(crash fix only)* - #42547 bake: re-arm the memory visualizer timer when it fires - #42733 dev server: make a client script request wait for the bundle in flight - #42828 bake: serve routes from a router root outside the project root instead of aborting or answering 404 - #42831 bake: resolve app.root and router roots through one checked join - #42836 bake: report route scan errors instead of aborting, and fail bun build --app on them *(crash fix only)* - #42840 dev server: map a router type's server entry point to the root route of that type - #42862 Bun.serve: return before a pending app.plugins setup() settles *(crash fix only)* - #42920 Do not create a mimalloc heap per FileSystemRouter, reload() or :nth-child(An-B) selector - #42934 dev server: register a client component without evaluating it - #43329 dev server: check the route bundle index of a client script URL before Index::init - #44249 fs.watch: read each directory and close it before descending - #44344 Windows: fix a watcher panic and lost events in a burst of file changes, and a --hot that stops watching a deleted… - #44744 dev server: answer a cached-file lookup only for a graph that bundled the file - #44746 dev server: keep an importer in its own graph when an import fails or is deleted **`Bun.serve`, sockets, HTTP, WebSocket, HTTP/2, QUIC, DNS** (28) - #42667 Reland "usockets(windows): keep a closed poll alive until the outer tick and libuv are done with it" (#39643) - #33015 fix(windows): segfault in uv__wake_all_loops after system resume *(crash fix only)* - #35761 node:quic: detach lsquic ctx pointers before the finalize-order sweep at worker VM teardown - #37082 Bun.serve: terminate FIFO/pipe file responses at EOF - #38024 dns: keep the c-ares uv_poll_t alive while its poll callback is on the stack (Windows) - #38636 serve: fix route use-after-free after reload() with tls.serverName *(crash fix only)* - #40888 server.fetch: copy a Headers argument instead of adopting the wrapper's pointer - #41337 Update lsquic to 4.9.4 and free unsent stateless resets on destroy *(crash fix only)* - #41384 usockets: hold a tick level for the whole of close_all - #41412 Windows: wait for close completions when closing a worker's uv loop - #41516 node:http2: handle an empty byte range in respondWithFile and respondWithFD - #41521 udp: report every binaryType from the getter, reject a dgram bind of the other family *(crash fix only)* - #42188 net: do not assert a two-character host in SocketAddress.parse - #42210 libuv(windows): keep a pipe's completed read counted until its read callback returns - #42334 fetch, Bun.serve: throw a RangeError for Headers that total 4 GiB or more *(crash fix only)* - #43738 usockets: close a socket whose resume the kernel refuses from the loop, not from the caller - #44338 node:http: response trailers travel with the end call of the response *(crash fix only)* - #44433 bake: make the parked-request list non-owning and look up the DevServer when a plugin load settles - #44533 node:quic: capture the handshake while the conn is alive, set the application at session creation - #44734 Bun.serve: answer HEAD for an S3-backed Blob body without an S3 stat - #44751 node:quic: close() waits only for opened streams, and lsquic sends no GOAWAY before HTTP/3 starts *(crash fix only)* - #44897 node:http2: throw instead of panic when the native setNextStreamID() misses its argument - #45076 node:http2: let close() and destroy() win over the refusal of a request - #45341 uws: AsyncSocket::write takes a size_t length, so res.end() sends a body of 2 GiB or more whole - #45522 node:http2: throw for an ALTSVC frame that is too long and for a pushPromise id that is not a stream id - #45676 node:quic: do not reset a stream lsquic has already finished - #45822 node:quic: name a stream in queued session events by a per-session key, not by its address - #45858 Bun.serve WebSocket: a message that does not fit in memory fails one connection, not the server *(crash fix only)* **Streams, Blob, S3, files, `node:fs`** (28) - #33845 io: propagate IoRequestLoop init failure instead of aborting *(crash fix only)* - #36365 prompt: drop debug_assert that rejects answers containing CR - #37090 Deliver FIFO bodies whose writer connects after the reader opens *(crash fix only)* - #38039 node:fs: stop fs.copyFile(src, "") from segfaulting on Windows - #38653 shell(cp): reject copying a directory into itself; walk cp trees without recursion - #39207 Convert scope-object receivers in the chaining functions and inspect.custom fallbacks - #39390 Blob deserialize: reject over-long paths, treat size >= MAX_SIZE as unknown, make slice() non-panicking - #39639 fetch: drop the upload and drain hop refs at VM teardown *(crash fix only)* - #40008 inspect hooks: copy user options with putDirectMayBeIndex *(crash fix only)* - #40462 Windows: FileSink.start({ path }) on a live writer: hand the writer a libuv fd and close the old source *(crash fix only)* - #41440 node:fs: pass the buffer to the read/readv/write/writev callback on error - #41584 Walk the timer pairing heap without recursion - #41608 native-readable: accept a stream with no native handle - #41710 JSSink write(): convert the chunk before resolving the native sink *(crash fix only)* - #42711 webstreams: bound the native recursion through a chain of tees or text streams - #43264 fetch: reject a file: URL whose path has an encoded NUL - #43709 s3: fix double free of a multipart part's bytes on worker terminate - #43950 streams: link readers and writers last, reject their promises as handled - #44036 PipeReader: label a chunk Eof only when the reader is at its end - #44181 streams: throw instead of aborting when a direct stream's text sink cannot take a string chunk - #44195 fs: validate POSIX directory records in one parser, report a malformed record as EIO *(crash fix only)* - #44269 streams: join the string chunks of a text consumer with one allocation - #44490 watch(windows): report a failed child spawn as an error instead of a panic *(crash fix only)* - #44954 process.stdout/stderr with no FileSink: write synchronously, reset after a failed write *(crash fix only)* - #45004 streams: leave a stream alone when a consumer fails to lock it - #45521 FileSink: throw ERR_ILLEGAL_CONSTRUCTOR from the constructor that script reaches by writer.constructor - #45738 s3: own the Blob store across the calls that run user JS - #45975 node:stream: do not touch the web controller after the web side is done **Node-API, V8 API, `bun:ffi`, `process.dlopen`** (15) - #36609 napi: implement uv_cwd on POSIX - #37989 bun:ffi: stop cc() from turning non-numeric pointer arguments into garbage pointers - #38057 bun:ffi: make cc() reject non-numeric i64/u64 arguments instead of passing garbage - #38425 bun:ffi: throw on an empty cc() source array instead of panicking - #39652 napi: implement uv_async_t, uv_queue_work and uv_default_loop on posix - #39805 Share one handle scope implementation between Node-API and the V8 API - #39892 napi: implement uv_idle_t, uv_prepare_t, uv_check_t and uv_timer_t on posix - #40144 bun:ffi: return undefined for a NULL napi_value from cc() and throw the scheduled napi exception - #40773 bun:ffi: add the full byteOffset in read.*, do not truncate it to int32 - #41704 napi: hand the thrown value to napi_get_and_clear_last_exception after napi_run_script - #42960 process.dlopen: run a V8 addon's init function after dlopen() returns - #43797 Fix debug assertion on an empty error message from a V8 addon or SQLite *(crash fix only)* - #43802 bun:ffi: throw a TypeError when a cc() symbol is called after its library's close() - #43940 napi: fail with ERR_BUFFER_TOO_LARGE instead of aborting above the ArrayBuffer limit *(crash fix only)* - #44921 bun:ffi: pad a short call to a cc() symbol with undefined **`node:vm`, workers, process, timers** (19) - #34623 node:vm: run DONT_CONTEXTIFY contexts directly against the real global - #32839 node:vm: reject invalid cachedData instead of crashing - #36921 error printer: clear the pending exception when formatting a non-Error uncaught value throws - #37270 error printer: one render per error, [Circular] under the key that closes the cycle - #38740 bun:test: give each VM its own fake clock *(crash fix only)* - #39864 Report a refused HTTP, bundle, IO or process waiter thread as an error instead of a crash *(crash fix only)* - #39992 process: deliver exceptions reported against a node:vm context to uncaughtException - #41654 node:vm: give each SourceTextModule request the import attributes of the declaration that created it *(crash fix only)* - #41739 Do not forward the inherited IPC channel to spawned scripts and tools - #41769 node:vm: stop compiling accepted cachedData, report each cachedData decode to the GC *(crash fix only)* - #42045 bun:test fake timers: never move the fake clock backwards - #42308 process.execve: throw instead of aborting for a string past the string limits - #42734 node:vm: report cachedData of 2 GiB or more as rejected instead of aborting - #42843 process.dlopen: reject a filename of PATH_MAX or more before dlopen() - #43500 process: accept SIGSTKFLT, SIGPOLL and SIGPWR, and emit every name of a signal number *(crash fix only)* - #44486 worker: stop the start sequence when a handler it calls stops the worker - #44771 timers: allocate ids from one 64-bit counter that never wraps - #44837 --hot: defer a reload during the preloads, and report a reload that cannot start - #44991 Fix a use-after-free in the VM ref-string intern for a string over the length limit **Shell, spawn, CLI, `bun test`, `bun install`** (31) - #30642 Fail fast at startup when simdutf has no usable implementation for this CPU - #34223 Fix four crashes: HTMLRewriter disturbed body, S3 locked-stream upload, ConnectionsList closed parser, shell brace… *(crash fix only)* - #34884 Guard the console and test-runner formatters against native stack overflow on deeply nested values *(crash fix only)* - #36584 process.chdir: publish an immutable cwd slice so no thread sees a torn cwd - #37135 bun test --parallel: hold the JSC API lock while draining the worker's final IPC backlog - #37527 shell(mv): report ENAMETOOLONG instead of panicking when a source name does not fit the path buffers - #37528 cli: stop aborting on absolute script paths longer than 1024 bytes on Windows - #38162 shell(cp): report ENAMETOOLONG instead of panicking on operands longer than the path buffers - #38205 shell(windows): report ENAMETOOLONG for operands that do not fit the path buffer - #39010 bun test: exit through the VM teardown path when --bail stops a run - #39104 bun test: report over-long coverage dir, JUnit outfile and bunfig root instead of panicking *(crash fix only)* - #39638 shell(cat): serve a second cat on the same stdin instead of hanging or panicking - #39641 usockets: report an out-of-descriptors event loop init as an error, not a crash *(crash fix only)* - #40181 shell: stop deeply nested if clauses from overflowing the parser stack - #40885 shell: throw instead of panicking when a ReadableStream is used as a redirect - #41155 ipc: send a queue item larger than 2 GiB in capped write requests - #42298 bun:test: print String objects with 16-bit storage correctly - #42577 bun:test: root the return values toHaveReturnedWith collects - #43606 shell(windows): report a failed pipe reader start through on_reader_error instead of leaking the subprocess *(crash fix only)* - #43838 node:cluster: read a worker's `ack` and `addressType` in the primary only when they are int32 - #44172 node:cluster: refuse a descriptor of the wrong kind in the primary *(crash fix only)* - #44185 node:cluster: one handle for each descriptor that workers name *(crash fix only)* - #44491 bun test: run every callback when native code leaves an exception pending *(crash fix only)* - #44694 shell mv: refuse to copy a directory into itself on the cross-device fallback - #44752 shell: take the command-substitution capture and drop its NUL bytes - #44981 shell: reject NUL bytes in .cwd() and .env() at the native setters - #45206 ini: reject a source of 2 GiB or more in Parser::parse instead of aborting on an int cast *(crash fix only)* - #45348 bun test: fix a segfault in .not.toThrow(Class) when Symbol.hasInstance accepts a thrown string, symbol or BigInt - #45649 shell: replace the output counters in mkdir, cp, ls and touch with the OutputTask queue - #45792 bun test: SIGKILL a spawnSync child that is still running 500 ms after the test's timeout *(crash fix only)* - #45910 create: own the remote-template response buffers instead of parking them in the CLI arena **Web APIs, Buffer, encoding, URL, crypto, zlib, SQLite, Redis and the rest** (96) - #29709 console: guard JSX/Proxy recursion in Bun.inspect (stack overflow SIGSEGV) - #30817 console.takeHeapSnapshot: clear prior snapshots before building - #30956 spawnSync: make signal-forwarding register/unregister safe for concurrent callers *(crash fix only)* - #31505 node:zlib: reject invalid brotli flush values at validation *(crash fix only)* - #31735 node:path: fix win32 drive-relative resolve on non-Windows hosts *(crash fix only)* - #32085 Fix crash when RedisClient onclose/onconnect is set to a non-callable - #32240 Fix BroadcastChannel custom inspect crash with numeric option keys - #33181 Reject interior null bytes in Bun.mmap, Glob.scan, and FileSystemRouter paths *(crash fix only)* - #33752 node:crypto: validate EC JWK private scalar matches public point in createPrivateKey - #34976 spyOn: install and restore through one writer that throws when the object refuses *(crash fix only)* - #35562 structuredClone: purify NaN in deserialized Date timestamp so getTime never returns a forged JSValue - #35618 napi(windows): load addons that import node.exe without win_delay_load_hook - #35757 Coerce later arguments before capturing input buffers in Bun.Transpiler and Bun.RedisClient - #37252 Report UTF-16 to UTF-8 encode counts through size_t so exactly 2^32 written bytes doesn't wrap to 0 - #37338 node:module: build require.cache without user-writable globals and propagate its exceptions *(crash fix only)* - #37340 redis: accept unsubscribe acks that arrive outside subscriber mode - #37370 Error.appendStackTrace: make appending an error's trace to itself a no-op - #37443 node:crypto: fix null deref when worker.terminate() lands during an EC JWK private key import - #37448 jsc: check for exceptions before using a stored constructEmptyArray result *(crash fix only)* - #38009 MessagePort: fix a heap-use-after-free in contextDestroyed(), release ref() when the last 'message' listener is rem… *(crash fix only)* - #38469 napi: settle or refuse async work queued during VM teardown instead of taking a ticket - #38708 Handle 16-bit module sources in the error preview, the new-position fix-up and the REPL *(crash fix only)* - #38821 process.env: make a failed env build throw instead of aborting (Windows 0xC0000409 on Bun.$ / Bun.sql / process.env… - #38871 process.env: coerce to string on every execution of an assignment, not just the first - #38877 cli: exit 128 + signo when bun cannot die from a re-raised signal (bun as container PID 1) - #38926 Clear the inherited signal mask at startup and exec children with an empty one *(crash fix only)* - #39382 Make a failed util.inspect load throw from custom inspect functions instead of aborting - #39481 Always create the error when a native error message exceeds the string length limit - #39651 performance: keep the user timing entry counts exact after clearMarks(name) and clearMeasures(name) - #39775 Turn seccomp SIGSYS traps into ENOSYS so the syscall fallbacks run on Android - #39968 process.dlopen: replay a non-context-aware V8 addon only while no other live VM owns it - #39975 watch: report a failed reload exec as an error instead of a panic *(crash fix only)* - #40346 Give Glob's native scan methods their own private names - #40554 node:crypto: copy password and salt for async pbkdf2 and scrypt - #40567 url: reject URL-encoded input over the WTF decode limit instead of aborting - #40577 url: throw a RangeError instead of aborting when URLSearchParams or FormData outgrows its Vector - #41073 Store array-index property names as indexed properties in native object builders - #41137 Write the sampling profiler report at exit from Bun, not JSC's atexit hook - #41365 webview: fail only the view when WebKit lacks initWithDirectory: - #41574 Decode a private copy of a JS buffer in the UTF-8 decoders *(crash fix only)* - #41652 console: read a BigInt depth option by value in console.dir - #41749 Startup: reopen fd 0-2 as /dev/null only when the fd is closed - #41819 Report an incoherent BUN_JSC_* option combination as a configuration error, not a crash *(crash fix only)* - #42158 webview: reject malformed Chrome replies instead of crashing - #42179 shell: clamp a `> ${buf}` redirect to the target buffer's live length - #42187 node:crypto: throw ERR_OUT_OF_RANGE for >2 GiB buffer arguments instead of aborting - #42191 URLPattern: throw instead of aborting when a pattern string passes the string limit - #42192 Copy WebAssembly.Memory bytes for native borrows that outlive the call *(crash fix only)* - #42198 Make Bun.$, Bun.sql, Bun.postgres and Bun.SQL custom value getters so reifying the Bun object passes exception chec… - #42203 node:fs: fs.read into a WebAssembly.Memory view writes into the block a grow freed - #42214 Headers: throw a RangeError instead of aborting when the set-cookie list cannot grow - #42218 Headers: throw instead of aborting when a value passes the string length limit - #42220 URLPattern: throw instead of aborting when the token list cannot grow - #42225 Throw ERR_STRING_TOO_LONG from Bun.wrapAnsi instead of aborting when the output passes the string length limit - #42226 Throw instead of aborting when a MIME string does not fit in a string *(crash fix only)* - #42237 Bun.Cookie: throw instead of aborting when the Set-Cookie string passes the string length limit - #42249 Copy a shared input before libdeflate compresses it in Bun.gzipSync and Bun.deflateSync - #42253 bun test: walk nested describe scopes without native recursion - #42259 Throw instead of aborting when a domainToASCII host passes the string length limit - #42310 Parse a private copy of a shared or resizable buffer in Bun.Transpiler, Bun.markdown, Bun.YAML and Bun.TOML *(crash fix only)* - #42312 YAML, JSON5, XML stringify: throw instead of aborting when the output passes the string length limit - #42318 Bound libdeflate's emit path so a racing input cannot overrun the output - #42338 inspector: check the type of process.argv in getModuleGraph - #42364 node:perf_hooks: do not truncate the monitorEventLoopDelay resolution to int32 - #42412 transpiler cache: reject an entry with no sourcemap section - #42479 worker_threads: do not abort when markAsUntransferable/markAsUncloneable gets a WebAssembly GC reference - #42517 EventTarget: skip a listener object that has no realm - #42518 fs.Stats: make the date accessors define the property like Object.defineProperty *(crash fix only)* - #42575 Stop natives from writing onto a foreign `this` with putDirect: process.ppid, require.cache, StringDecoder, the nat… *(crash fix only)* - #42631 JSStringView: pin the cell that owns the borrowed characters - #42660 bun_core: read /dev/urandom when getrandom(2) answers ENOSYS or EPERM - #42780 node:crypto: treat a name too long to convert to UTF-8 as unknown instead of aborting - #42782 node:crypto: throw ERR_OUT_OF_RANGE for a passphrase larger than INT_MAX bytes - #42856 url: do not abort when a host is too long for the IDNA conversion buffers - #42868 sqlite, console, process: do not abort on a string too long to convert to UTF-8 *(crash fix only)* - #42941 Bun.sliceAnsi: throw instead of aborting when the result passes the string length limit - #43058 Bun.serve: fix crash and cross-request 500 when inspecting a non-Response return value throws - #43904 JSC bindings: build property keys from a BunString through Bun::toIdentifier - #44124 Bun.Image: decode WebP into a Bun-owned canvas and read ICCP without the demuxer *(crash fix only)* - #44190 Convert scope-object receivers before Buffer read*/write* and vm.Script describe them - #44211 Stop getsockname(out), useFakeTimers() and the stream source pull() from writing onto a caller's object with putDirect - #44295 bun test --coverage: append a final newline to a text that lacks one *(crash fix only)* - #44360 rust-argon2: return OutOfMemory instead of aborting when the memory cost cannot be allocated - #44421 node:zlib: free zstd's workers before the dictionary they read - #44521 util.parseArgs: pick the default args start from a per-VM eval flag, as Node v26 does *(crash fix only)* - #44740 structured clone: tolerate a zero-sized shared WebAssembly.Memory in computeMemoryCost() - #44759 HTMLRewriter: park a suspended handler's token before the output flush - #44907 Builtins section format 2: an engine stamp says which buns compile its modules - #45188 Reject an oversized WebCrypto cipher output instead of aborting - #45354 Throw for a `file:` URL whose path is not UTF-8 on Linux and macOS, through one `fileSystemPath()` accessor *(crash fix only)* - #45608 ipc: refuse an over-long message before the receive buffer stores it - #45624 webcrypto: write the key type into the X25519 structured-clone record - #45625 node:sqlite: refuse session.close() and Symbol.dispose inside a SQLite callback - #45653 glob: a group with `?` or a class matches when an alternative takes 64 bytes or more - #45820 Bun.file, S3Client.file and Bun.write no longer keep a buffer path alive forever - #45832 `bun check`: fix a panic on `export *` without a module specifier, and a false error for one in parentheses ### Already fixed on `main`, or duplicates of a pull request above Already fixed: #27323 #30401 #31011 #31206 #31566 #31626 #31695 #31702 #31945 #32773 #34154 #34697 #34744 #34964 #35655 #35816 #36020 #36181 #36296 #36342 #36581 #36602 #36807 #36818 #36857 #37172 #37235 #37239 #37267 #37420 #37731 #37914 #38113 #38119 #38509 #38514 #38540 #38975 #39410 #40749 #41163 #41171 #42108 #43085 #43230 Duplicates: #45654 #29986 #33378 #36895 #37070 #37639 #38014 #39021 #41266 #42250 #42951 #43238 #44259 #45335 #45565 #45726 #45965 Fixes #5019 Fixes #6106 Fixes #10690 Fixes #10886 Fixes #13566 Fixes #14745 Fixes #15551 Fixes #20454 Fixes #21310 Fixes #29145 Fixes #30454 Fixes #30613 Fixes #30766 Fixes #32103 Fixes #32142 Fixes #32183 Fixes #32212 Fixes #39060 Fixes #42296 Fixes #42931 Fixes #43671 Fixes #44201 Fixes #44735 Fixes #44783 Fixes #45198 Fixes #45327 Fixes #45491 Fixes #45721 --------- Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

robobun assigned dylan-conway Aug 21, 2026

github-actions Bot added the claude label Aug 21, 2026

robobun mentioned this pull request Aug 21, 2026

Fix --watch reload panic when the executable has been deleted or replaced #31691

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This was referenced Aug 28, 2026

watch: close non-CLOEXEC fds across a --watch reload on macOS #40706

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watch: name the errno when the process reload fails #40851

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robobun force-pushed the farm/f5b6299f/watch-reload-exec-failure branch from 22aff80 to d41b244 Compare September 30, 2026 19:49

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robobun marked this pull request as draft September 30, 2026 19:54

claude Bot reviewed Sep 30, 2026

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robobun mentioned this pull request Oct 3, 2026

watch(windows): report a failed child spawn as an error instead of a panic #44490

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robobun mentioned this pull request Oct 15, 2026

--hot: defer a reload during the preloads, and report a reload that cannot start #44837

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Jarred-Sumner mentioned this pull request Oct 19, 2026

Hardening: fix crashes across the runtime, bundler, dev server, shell and CLI #46021

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		// Once the running binary is unlinked, /proc/self/exe reads "<path> (deleted)". After an
		// in-place replacement (`bun upgrade`, a reinstall) the new binary is at <path>: exec it.

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