PipeReader: do not read again after a failed read by robobun · Pull Request #43920 · oven-sh/bun

robobun · 2026-09-24T20:50:12Z

Problem

spawn-stdio-syscall-error.test.ts fails with "lost": -78925 in 95 of the last 400 CI builds, all on Alpine.
After a recv() on a child's stdout fails, bun calls recv() again. The later bytes come out as 'data' before 'error'.
Cause: read_loop (src/io/PipeReader.rs) delivers the bytes it holds before it reports a failed read. The consumer pulls again during that delivery.

Fix

read_once sets a new flag, READ_FAILED. begin_read tests it with IS_PAUSED, so read, read_into and on_poll do nothing until the parent calls start(). The frame that saw the failure still reports the error once.
Verified: spawn-stdio-syscall-error.test.ts, four new tests count recv() calls after the failure. Three fail on main, all pass here. Other suites: Notes.
Self-reviewed: 13 concerns raised, 10 addressed. Kept: the KEEP_ALIVE renumbering (one aarch64 immediate), no test for the start() reset, the tests' timing precondition (Notes).

Background

PosixBufferedReader reads pipes and sockets for 14 parents (streams, subprocess stdio, the shell). A streaming parent runs JS inside on_read_chunk, and that JS can pull again.
Considered closing the reader before the delivery, as for EOF: the nested pull reports a clean EOF. Considered a guard in native-readable.ts: Bun.spawn streams keep the bug.

Downsides

One more instruction per read entry on aarch64, and one per loop pass on x64. .text grows 512 bytes.
After a read error, bun run --filter no longer drains that pipe at exit. No other parent reads after an error (Notes).

Notes

CI data. Buildkite annotations of the 400 finished builds #119336 to #120061: the test "node:child_process: stdout delivers every byte read before the error" is in a flaky-new annotation on 95 builds (Alpine 3.23 x64 98 entries, aarch64 42), and on 23 of the last 50. It started with the build of #43739, which added the test. Every lost value is a negative multiple of 1025. busybox head -c writes 1025-byte chunks, so several small recv() calls fill one pass of the loop and the injected 6th call lands inside it. GNU head fills the pass with one recv(), so the glibc lanes do not see it.

Repro without Alpine. A writer that writes 1025-byte chunks (8 MB) with the test's shim and SPAWN_FAULT_RECV_AT=6. A shim that logs each call shows the two cases:

good: recv#2..#5 return bytes, recv#6 len=65536 (a JS pull, read_into)            -> EIO, fd closed, no later recv
bad:  recv#2..#5 len=262144, 247794, 219094, 189369 (one pass), recv#6 len=153494 -> EIO
      recv#7 len=65536 -> 65536 bytes, recv#8 ... (reads go on)

The existing lost: 0 assertion with that writer, 50 runs each on debug builds: main fails 22 (up to 91 recv() calls after the failed one), this PR fails 0 and makes 0 calls after the failure.

New tests. The shim gets SPAWN_FAULT_RECV_MID_FILL=1 (the recv() that directly follows a recv() that returned bytes fails) and SPAWN_FAULT_READS_AFTER=path (how many recv() calls came after the failure). The writer is sh -c 'read go; printf hello; read done'. The parent sends go from setImmediate, when its first read is parked, so the bytes arrive through the poll and the failure is in the same pass.

test	main	this PR
node:child_process: `'data'`, then `'error'`	fails, 1 `recv()` after the failure	passes
node:child_process: `destroy()` in that `'data'` listener leaves only `'close'`	passes	passes
Bun.spawn: the chunk, then the read rejects	fails, 1	passes
Bun.spawn: `cancel()` after that chunk resolves	fails, 1	passes

The destroy() and cancel() cases close the reader inside the delivery. They run the branch that skips the error report for a reader that is already done. That branch tests is_done(), so a parent that tears the reader down with deinit() inside the delivery gets no report either. No parent does that today, so no test covers it. 20 runs of each fixture outside the test runner: 1 call after the failure on main, 0 here, every run. The existing flaky test and its fixture are unchanged.

Failure path, BUN_DEBUG_FileReader=1. Same lines on main and on this PR: onReadChunk() = 5 (progress), onPull(65531) = 0, onPull(65531) = pending, then the rejection. On main the = 0 pull is a real recv() that returns EAGAIN. Here it stops at the gate.

Costs, measured. Release builds (bun run build:release) of main 73df7bb and of this PR, linux-x64. The aarch64 rows are from cargo rustc -p bun_io --release --target aarch64-unknown-linux-gnu -- --emit=asm, which is the crate alone and not the linked binary.

what	main	PR
`.text` (`llvm-size -A`, `bun` and `bun-profile`)	58,154,396	58,154,908 (+512)
file size of the stripped `bun`	80,844,320	80,844,320
reader symbols (`llvm-nm -S`)		+178 bytes: `read_loop` +158, `start` +16, two callers with `start` inlined +6 each, `read` -3, `read_once` -5. 0 new symbols
x64 gate in `read`, `read_into`	`testl $0x200`	`testl $0x600`, +0 instructions
x64 `read_loop` check after a delivery	`testb $0x31, 0x58(%rsi)`	`movzwl 0x58(%r10), %ecx` and `testl $0x431, %ecx`, +1 per pass
x64 `start`	57 instructions	59
aarch64 gate in `read`, `read_into`, `on_poll`	`tbnz w8, #9`	`tst w8, #0x600` and a branch, +1
aarch64 `read_loop` check after a delivery	`mov w9, #49` and `tst w8, w9`	`mov w9, #1073` and `tst w8, w9`, +0
`size_of::<PosixBufferedReader>()` (`-Zprint-type-sizes`)	96	96
lock-step stream, 1000 chunks of 4096 bytes, `recv()` calls (LD_PRELOAD counter, 3 runs each)	child_process 3000, Bun.spawn 3003	3000, 3003
same, libc `epoll_ctl` calls	2	2
2 GiB through `child.stdout` `'data'`, 8 interleaved rounds	mean 1195 MiB/s (962 to 1440)	mean 1209 MiB/s (986 to 1417)

strace, perf, valgrind and bloaty are not installed in the container that ran this. The syscall counts come from an LD_PRELOAD counter that interposes recv and epoll_ctl. There are no perf stat instruction counts.

Audit of the parents. All 14 on_reader_error implementations and every external read(), read_into(), watch(), start() call were read. After an error FileReader, SubprocessPipeReader, Terminal and FileResponseStream close the reader. The install, cron, multi_run and test-worker parents only count the fd as finished. multi_run.rs drains at exit only when ended is not set, and its on_reader_error sets it, so it never read after an error. The lifecycle script and git runners replace the reader before the next spawn. The shell IOReader is the one parent that can start the same reader again, through start(), which clears the flag. It calls start() only when the poll is not registered. After a failure in a poll-driven read the fired poll still counts as registered, so a later reader of the shell's stdin waits. main has the same hang, because nothing arms the poll again after an error. I did not reproduce it, and this PR does not fix it. A fix that restarts the reader must go through start(). filter_run.rs (drain_and_close_pipes) reads again on process exit after an error. On main that read can report the same fd twice and can pick up bytes that arrived after the failure. With the flag it is a no-op, and deinit() follows. The flag is set only in read_once, so a failed poll registration, which FileResponseStream answers with a second read(), is unchanged.

Self-review, the 3 concerns that did not change the diff.

KEEP_ALIVE moves from bit 10 to bit 11. Nothing depends on its value. It keeps IS_PAUSED | READ_FAILED one contiguous mask, which aarch64 encodes in the tst itself. With bits 9 and 11 the gate needs one more mov.
No test restarts a failed reader through start(). Only the shell's shared stdin reader can do that, and a test needs a failed read on the shell's own stdin.
The new tests need the first bytes to arrive through the poll, not through a pull. If that ever changes, the tests pass on a broken build too: they can miss the bug, they cannot fail without it.

The concerns that changed the diff: an unreachable READ_FAILED test in try_register_poll (removed), no check in from() for a failed reader (a debug_assert! now), the gate's contract was not written down (doc on begin_read), no coverage for a consumer that stops inside the delivery (two tests), a mask constant named like the done() method (removed), a duplicated mask (one use now), a 300-character doc line (one short line now), the --filter drain (in Downsides), test titles that claimed an order the fixture did not record (the events now hold 'data' and the chunk), and a constant name in the test.

After review. The error report is now skipped for every done state (is_done()), not only IS_DONE: a reader torn down with deinit() sets CLOSED_WITHOUT_REPORTING only. The comments on the flag are cut to one line.

Suites run on the debug build with the fix. spawn-stdio-syscall-error.test.ts (17 pass, 8 runs in a row), spawn-streaming-stdout.test.ts, spawn-maxbuf.test.ts (16), spawn-stdin-readable-stream.test.ts (37), spawn.test.ts -t stdout (25), child-process-stdio.test.js (9), process-stdin.test.ts (22), body-clone.test.ts (85), node-stream.test.js (112), bunshell.test.ts (436), filter-workspace.test.ts (89). cargo check -p bun_io for aarch64-apple-darwin, x86_64-pc-windows-msvc, x86_64-unknown-freebsd and aarch64-unknown-linux-musl. On an earlier revision of this diff child_process.test.ts gave 81 pass and 2 fail ("should allow us to spawn in the default shell", "extra stdio pipes are not double-closed on GC"). The same 2 fail on a debug build of main in the same container.

Load. With the default 5 s test timeout and three copies of the file running at once on the debug build, tests of this file time out, the existing node:child_process ones too. No run showed a wrong value. CI runs the file in the parallel batch with a 90 s test timeout (270 s on the ASAN lane, scripts/runner.node.ts).

Not covered. macOS and FreeBSD use the same reader, but the tests need LD_PRELOAD and run on Linux only. The Windows reader is completion based and has no pass that holds bytes when a read fails.

no test proof · iteration 0 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/bun/spawn/spawn-stdio-syscall-error.test.ts

A read that fails after the same pass of the read loop already gathered bytes delivers those bytes first and reports the error after. While the bytes are delivered the consumer can ask for more, and that nested read reached the fd again: only the one call failed, so it succeeded and its bytes came out as data ahead of the error. read_once() now marks the reader READ_FAILED when a read fails with a non-retry errno. begin_read() tests it together with IS_PAUSED, so read(), read_into() and on_poll() do nothing until the parent calls start() again, and the read loop stops when a nested read has failed. The frame that saw the failure still owns the error and reports it once, unless the consumer closed the reader in the meantime.

robobun · 2026-09-24T20:50:30Z

Status: closed. #43900 carries the same fix and was opened first. Review #43900.

How I reproduced it

bun bd test test/js/bun/spawn/spawn-stdio-syscall-error.test.ts on main: three of the four new tests fail with readsAfterError: 1. With this branch all 17 tests pass.
The CI failure itself, without Alpine: the test's shim with SPAWN_FAULT_RECV_AT=6 and a child that writes 8 MB in 1025-byte chunks, as busybox head -c does. On main the lost: 0 assertion fails in 22 of 50 runs. With this branch it fails in 0 of 50.

coderabbitai · 2026-09-24T20:55:05Z

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src/io/PipeReader.rs

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Walkthrough

POSIX readers now track non-retry read failures and suppress further reads until restarted. The read loop delivers bytes already read before reporting an error. Tests cover this behavior in node:child_process and Bun.spawn streams, including consumers that stop after receiving a chunk.

Changes

Pipe read failure handling

Layer / File(s)	Summary
Reader failure state and read loop `src/io/PipeReader.rs`	Adds `READ_FAILED`, shifts `KEEP_ALIVE` to bit 11, and clears the failure flag on `start()`. The read loop stops after a failure and dispatches the error only when the reader is not done.
Mid-fill failure tests `test/js/bun/spawn/spawn-stdio-syscall-error.test.ts`	Extends the receive shim to fail after a successful read. Tests check byte counts, data-before-error ordering, and behavior when stream consumers destroy or cancel after receiving the chunk.

Suggested reviewers: jarred-sumner, dylan-conway

Priority: ➖ Normal

Merge Risk: ⚪ Minimal · up to 565e0

Pipe readers now deliver already-read bytes before reporting a non-retryable error and stop further reads until restarted. The inspected transfer and reentrant paths preserve that behavior, leaving no actionable merge-blocking risk.

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Title check	✅ Passed	The title clearly identifies the main change: preventing PipeReader from issuing another read after a failed read.
Description check	✅ Passed	The description explains the problem, the fix, trade-offs, limitations, and extensive verification results. It does not use the template headings verbatim, but it fully covers what the PR does and how…

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Inline comments:
In `@src/io/PipeReader.rs`:
- Around line 852-854: Update the error guard in PipeReader’s on_read_chunk flow
to use is_done() instead of checking only PosixFlags::IS_DONE. Preserve the
existing on_error call for nonterminal readers, and suppress it for all terminal
reader states, including CLOSED_WITHOUT_REPORTING.

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The read loop reports a failed read after it delivers the bytes it holds. A consumer can close the reader during that delivery, and it can also tear it down with deinit(), which sets CLOSED_WITHOUT_REPORTING and not IS_DONE. Test is_done() so that both get no report.

robobun · 2026-09-24T21:15:53Z

^{Updated 3:03 PM PT - Sep 24th, 2026}

❌ @robobun, your commit 565e0c5 has 1 failures in Build #120423 (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 43920

That installs a local version of the PR into your bun-43920 executable, so you can run:

bun-43920 --bun

claude

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

claude

Code review completed

Nothing new to post: everything this review found is already covered by existing comments on this pull request or didn't merit a separate one.

This review covers commit 595686d, which is no longer the latest commit on this pull request; later commits are not covered by it.

…ntry The doc comment on READ_FAILED now says that nothing clears the bit. The tests now cover each way a consumer reaches the reader from inside the delivery of the bytes read before a failed read: - node:child_process with a 'data' listener (a pull, read_into). - node:child_process with 'readable' and read(): the reader is stopped at the highWaterMark and read() starts it again (read). - Bun.spawn with lazy: the reader starts at the first read. - Bun.spawn with the reader started at spawn. The writer waits for a line on stdin, so the first read is parked when the bytes arrive. The shim fails the recv() that follows the one that returned bytes and counts the recv() calls after it. This trigger comes from #43920. Each of the four fails without the change to begin_read, on a debug build and on a release build.

robobun · 2026-09-25T03:31:48Z

This PR and #43900 make the same change to read_once and begin_read in src/io/PipeReader.rs. The two conflict, so only one can merge.

PipeReader: do not read an fd again after a read on it fails #43900 was opened first (2026-09-24 15:57 UTC). Its first build, 120337, passed on all lanes, alpine included.
PipeReader: do not read an fd again after a read on it fails #43900 now has this PR's state-based test trigger (SPAWN_FAULT_RECV_MID_FILL, SPAWN_FAULT_READS_AFTER and the writer that waits for a line on stdin). Its commit message names this PR as the source.
With the build of PipeReader: do not read an fd again after a read on it fails #43900, the test file of this PR passes 17 of 17 in 3 runs. So the tests here do not need the reset in start() or the two extra checks in read_loop.
The difference that remains is the lifetime of the flag. Here start() clears it. In PipeReader: do not read an fd again after a read on it fails #43900 nothing clears it, and the doc comment says so. Nothing on main restarts a reader after a failed read.

I propose to keep #43900 and to close this PR. A maintainer can choose the other way: the fix is the same.

robobun · 2026-09-25T03:35:34Z

Closing: #43900 makes the same change to read_once and begin_read, was opened first, and now has this PR's test trigger. Only one of the two can merge, so #43900 is the one to review.

This PR had three more changes: it reset READ_FAILED in start(), it skipped the error report for a reader that the consumer closed during the delivery, and it stopped the read loop after a nested failed read. No caller on main needs them. The measurements and the audit of the 14 parents stay in the description above.

### Problem - `test/js/bun/spawn/spawn-stdio-syscall-error.test.ts` is red on alpine: `"lost": -82000`, not `0` (build 120303). #43739 added the case, not the bug. - `read_loop` (`src/io/PipeReader.rs:766`) delivers the bytes read before a failed read, then the error. The consumer asks for more inside that delivery, and the reader reads the fd past the error. The error comes late, or never. ### Fix - `read_once` sets `PosixFlags::READ_FAILED` on a fatal error, and `begin_read` does not read while it is set. The request parks, then `on_reader_error` rejects it. Nothing clears the flag. - Correct: libuv `uv__read` clears `UV_HANDLE_READABLE` before it reports a read error. - Verified: `test/js/bun/spawn/spawn-stdio-syscall-error.test.ts`, 17 pass. The four new cases fail without the fix. Suites: Notes. - Self-reviewed: 15 concerns raised, 14 addressed. Not taken: a flag reset in `start()`, which nothing on main needs. ### Background - `PosixBufferedReader` reads the fd behind subprocess stdio, file streams and the shell. Its parent gets `on_read_chunk`, then `on_reader_done` or `on_reader_error`. - `FileReader` is the parent behind a `ReadableStream`. `on_read_chunk` resolves the parked `pull()`, and the reaction runs before it returns. - Considered: a repeating shim failure hides the lost error. An error stored in `FileReader` first needs a callback in every parent. - #43920 is a newer PR with the same change. Its test trigger is here. ### Downsides - After a read error, a stream that ended with `'end'` now ends with `'error'`, as in Node. With no listener the process stops. - After a read error, `bun run --filter` no longer drains that pipe at exit. - Reads that do not fail pay nothing: `begin_read` tests one more bit. <details><summary>Notes</summary> **Trace without the fix** (bun 1.4.3-canary.1+367d939d9, shim logs each `recv()`, writer `dd bs=1025`). The debug build of main at 8d36bff does the same: 3 of 8 runs, two with no `'error'` and `lost` -7714150: ``` recv #5 len=262144 -> 95325 recv #6 len=166819 -> EIO (injected) same fill_scratch call as #5 JS data 95325 recv #7 len=65536 -> 65536 pull from inside the delivery, read_into recv #8 .. #116 to EOF {"received":452025,"got":8000125,"lost":-7548100,"events":["stdout.close","close"]} ``` No `'error'` event: the reads reached EOF before `on_reader_error` ran, and a stored error is only returned by a later pull. When the reads park first, `on_reader_error` rejects that pull and `'error'` comes late. That is the CI signature: the events match and `lost` is a negative multiple of 1025. **Why alpine.** In CI the failure is injected: the shim fails only the Nth `recv()`, so a later `recv()` succeeds and the extra bytes show. The failing `recv()` must follow bytes in the same wakeup. BusyBox `head` writes 1025 bytes at a time, so a wakeup often holds a short `recv()` and then the failing one. coreutils `head` fills the buffer in one `recv()`. The same run fails on debian when the writer is slow. With a writer that copies BusyBox `head` (stdio, 1024-byte buffer), the `RECV_AT=6` case fails 7 of 40 runs on bun 1.4.3-canary (release), and 36 of 40 when the writer also spins between chunks. This branch (debug): 0 of 120, and 0 of 60 with `dd bs=1025`. **With no shim.** A child with one AF_UNIX socket as fd 0 and fd 1 writes a line to stdout and reads stdin. The peer leaves that line unread, sends 8192 bytes and closes. The kernel gives the child 8192 bytes, then `ECONNRESET`, then EOF. | Runtime | stdin events | |---|---| | Node v26.3.0 | `'error'` `ECONNRESET` after 8192 bytes | | bun 1.4.3-canary.1+367d939d9 | `'end'` after 8192 bytes, no error | | this branch | `'error'` `ECONNRESET` after 8192 bytes | **The new cases.** Each one reaches the reader from inside the delivery in a different way. Whole-file runs of the describe block: | Case | Entry | Release, no fix | Debug, no fix | Debug, guard in `read_into` only | Debug, this branch | |---|---|---|---|---|---| | `child_process`, `'data'` listener | pull, `read_into` | fails 6 of 6 | fails 5 of 5 | passes | passes | | `child_process`, `'readable'` and `read()` | `set_flowing(true)`, `read` | fails 6 of 6 | fails 5 of 5 | fails 3 of 3 | passes | | `Bun.spawn`, `lazy` | pull, `read_into` | fails 6 of 6 | fails 5 of 5 | passes | passes | | `Bun.spawn`, reader started at spawn | pull, `read_into` | fails 6 of 6 | fails 5 of 5 | passes | passes | - The first three use counts: `SPAWN_FAULT_RECV_CAP=4096` makes every `recv()` short, so `fill_scratch` calls `recv()` again in the same wakeup. `SPAWN_FAULT_RECV_EAGAIN_AT=2` ends the first read loop, so the consumer's read parks and the next read is poll-driven. `SPAWN_FAULT_RECV_AT` then fails after bytes in that wakeup. For the `'readable'` case it is 19: #3 to #18 return 64 KiB, the highWaterMark, so the reader is stopped and `read()` starts it again. - The fourth uses state, and comes from #43920: the writer waits for a line on stdin, so the first read is parked when the bytes arrive. `SPAWN_FAULT_RECV_MID_FILL=1` fails the `recv()` that follows one that returned bytes, and `SPAWN_FAULT_READS_AFTER` counts the `recv()` calls after it. Without the fix it is 1. - With a count-based trigger and the reader started at spawn, the case passed without the fix on a debug build: the buffered reader that runs before JS reads `.stdout` took the bytes and the error. That is why this case uses state. - With the BusyBox-like writer at four speeds, the whole file passes 20 of 20 on this branch. **With the fix**, `CAP=4096 EAGAIN_AT=2 RECV_AT=5`: ``` recv #3 -> 4096, recv #4 -> 4096, recv #5 -> EIO JS data 8192 close(fd) JS error EIO ``` **Node.** libuv `uv__read` (`src/unix/stream.c`): on a read error other than `EAGAIN` it clears `UV_HANDLE_READABLE | UV_HANDLE_WRITABLE`, calls `read_cb` with the error, then stops the watcher. It calls `read_cb` once for each `read()`, so it never holds bytes and an error from one batch. **Placement.** EOF and the `maxBuffer` stop have the same guard at this site: `close_if_final` closes the reader before the final chunk is delivered. An error cannot use it, because a closed reader with no stored error reads as a clean end. For the same reason `READ_FAILED` is not part of `is_done()`. **Parents** (14 `BufferedReaderParent` implementations, what each does in `on_reader_error`): - 3 release the fd: `FileReader`, `SubprocessPipeReader`, `Terminal`. - 2 drop the reader: `FileResponseStream`, shell `subproc.rs`. - 8 only do accounting: `filter_run.rs`, `multi_run.rs`, `lifecycle_script_runner.rs`, `security_scanner.rs`, `git_runner.rs`, both cron jobs, test `Worker.rs`. `lifecycle_script_runner.rs` and `cron.rs` build a new reader with `init()` for each spawn. - 1 is shared and can restart: the shell `IOReader`. Only two read the same reader after an error. `filter_run.rs` `drain_and_close_pipes` reads once more at exit. That read is now a no-op, and `deinit()` follows. Before, it could reach a second terminal callback and decrement `remaining_fds` twice. The shell `IOReader::start()` does not restart a reader after a failed read on main, because the fired one-shot poll still counts as registered. The Windows reader gets one libuv callback for each read, so it has no bytes-then-error batch. **Left open.** - The flag is permanent. #39638 and #37901 change `IOReader::start()` to restart the shell's stdin reader. After this PR they must clear `READ_FAILED` there, or a `cat` that follows a stdin read error gets no data, no EOF and no error. - Not in this PR: a batch that stops because the buffer is full is labelled `ReadState::Eof` when the poll event carries the hangup (`read_state`, `None if received_hup`). `Bun.write(file, proc.stdout)` then writes 262144 of 400000 pending bytes and resolves. It is on main and in 1.4.3-canary, and this PR does not change it. It needs its own change. - Not in this PR: release the fd on a read error once, in `PosixBufferedReader::on_error`. #41456 names it as a follow-up. #41420, #41456 and #42150 did it for one parent each. **Suites run on the debug build:** `test/js/web/streams/streams.test.js` (624 pass), `test/js/node/stream/node-stream.test.js` (112 pass), `test/js/bun/spawn/spawn-streaming-stdout.test.ts` (pass), `test/js/node/child_process/child_process.test.ts` (81 pass, 2 fail in my container for reasons outside this change: "spawn in the default shell" reads an empty `$SHELL`, and "extra stdio pipes are not double-closed on GC" needs 5.0 s in a debug build against the 5 s timeout, its script prints `OK`). With this branch's build, the test file of #43920 passes 17 of 17 in 3 runs. #43790 is open and edits the comment above the failing case. It changes the event order in `native-readable.ts`, not the reader. </details>  --- **no test proof** · iteration 0 · platform-specific test(s) that do not run on this machine, deferring to CI, which covers all platforms: test/js/bun/spawn/spawn-stdio-syscall-error.test.ts

github-actions Bot added the claude label Sep 24, 2026

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Comment thread src/io/PipeReader.rs Outdated

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PipeReader: shorten the comments on READ_FAILED

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ci: retrigger

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robobun mentioned this pull request Sep 25, 2026

PipeReader: do not read an fd again after a read on it fails #43900

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robobun closed this Sep 25, 2026

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PipeReader: do not read again after a failed read - #43920

PipeReader: do not read again after a failed read#43920
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