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unknown error in execFileSync from node:child_process #31710
Description
What version of Bun is running?
1.3.14+0d9b296af
What platform is your computer?
Linux 6.8.0-111-generic x86_64 x86_64
What steps can reproduce the bug?
- create file
test.jswith the following content:
import { execFileSync } from 'node:child_process';
const stdout = execFileSync('./helpers/script.sh', ['hello''], {
encoding: 'utf8',
});
console.log(stdout);- create file
./helpers/script.shwith the following content:
echo "$1 $1";- run it with
bun test.js
What is the expected behavior?
in Node.js, it outputs
hello hello
What do you see instead?
in Bun it throws the following error:
1 | import { execFileSync } from 'node:child_process';
2 |
3 | const stdout = execFileSync('./helpers/script.sh', ['hello'], {
^
ENOEXEC: unknown error, posix_spawn './helpers/script.sh'
path: "./helpers/script.sh",
syscall: "spawnSync ./helpers/script.sh",
errno: -8,
spawnargs: [ "hello" ],
signal: null,
status: undefined,
output: [ null,
null, null
],
pid: undefined,
stdout: null,
stderr: null,
code: "ENOEXEC"
at spawnSync (node:child_process:226:22)
at execFileSync (node:child_process:264:54)
at /home/username/execFileSync.mjs:3:16
Bun v1.3.14 (Linux x64)Additional information
No response
Activity
robobun commentedon Jun 2, 2026
✅ Reproduced — an executable with no shebang makes
execvereturnENOEXEC; Node/libuv transparently retry the exec through the shell, Bun surfaced the raw error.Fix in #31717: on
ENOEXEC, re-execsh <file> <args...>(matching libuv/Node —$0is the resolved path,$1..the user args). CoversexecFileSync,spawnSync,execFile,Bun.spawn/Bun.spawnSync, and Bun Shell (also fixes #11563).github-actions commentedon Jun 2, 2026
Found 1 possible duplicate issue:
This issue will be automatically closed as a duplicate in 3 days.
🤖 Generated with Claude Code
spawn: retry via /bin/sh when exec returns ENOEXEC
spawn: retry via /bin/sh when exec returns ENOEXEC
Jarred-Sumner commentedon Aug 13, 2026
#11563 is the same underlying bug: running an executable script with no shebang makes execve fail with ENOEXEC, and Bun surfaces that instead of retrying through
/bin/shthe way Node does (Bun Shell shows it as "Exec format error"). The fix in progress covers spawn/spawnSync/execFileSync as well, so closing this as a duplicate; please follow #11563. Adding#!/bin/shto the script works around it today.Duplicate of #11563
Please add a 👍 or any extra details over there so it all stays in one place. If this is actually a different problem, say so here and we'll reopen.
(This comment was written by Claude, on behalf of the Bun team.)