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Ubuntu: stdout and stderr data is not emitted on child processes (with piped stdio) #42438

Closed as not planned
Closed as not planned
Ubuntu: stdout and stderr data is not emitted on child processes (with piped stdio)#42438
Labels
child_processIssues and PRs related to the child_process subsystem.

Description

@medikoo
medikoo
opened on Mar 22, 2022

Version

v18.0.0-nightly20220311d8c4e375f2

Platform

Linux parallels-Parallels-Virtual-Platform 5.13.0-37-generic #42~20.04.1-Ubuntu SMP Tue Mar 15 15:44:28 UTC 2022 x86_64 x86_64 x86_64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

Run node main.js having following two files in same folder:

child.js

console.log("Some text");

const interval = setInterval(() => {
	console.log("Other text")
}, 100)

setTimeout(() => clearInterval(interval), 1000);

main.js

const childProcess = require('child_process');

const child = childProcess.spawn('node', ['child.js'], { stdio: 'pipe'});

if (child.stdout) {
	console.log("Attach std listeners")
	child.stdout.on('data', data => console.log("Child stdout:", String(data)));
	child.stderr.on('data', data => console.log("Child stderr:", String(data)));
}

child.on('close', (...args) => { console.log("Child closed", args); });

How often does it reproduce? Is there a required condition?

Always

What is the expected behavior?

Expected output (e.g. observable on macOS) is:

Attach std listeners
Child stdout: Some text

Child stdout: Other text

Child stdout: Other text

Child stdout: Other text

Child stdout: Other text

Child stdout: Other text

Child stdout: Other text

Child stdout: Other text

Child stdout: Other text

Child stdout: Other text

Child closed [ 0, null ]

What do you see instead?

Attach std listeners
CLOSED [ 0, null ]

Additional information

When stdio is set to inherit then the child output is exposed as expected.

I observe it on every Node.js version I've tried (v14, v16, v17, and latest build)

Activity

  1. medikoo
    changed the title [-]Ubuntu: `stdout` and `stderr` data is not emitted on child processes (with piped stdin[/-] [+]Ubuntu: `stdout` and `stderr` data is not emitted on child processes (with piped `stdio`)[/+] on Mar 22, 2022

  2. ekalkutin commented on Mar 22, 2022

    @ekalkutin
    ekalkutin
    on Mar 22, 2022

    I ran some tests on Windows / WSL2 Ubuntu ( just to confirm it works on Node 17.7.1)

    uname -a
Linux RADIANT-XPS-17 5.10.60.1-microsoft-standard-WSL2 #1 SMP Wed Aug 25 23:20:18 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

    works as expected
    What is a reason you use nightly build ?

  3. medikoo commented on Mar 22, 2022

    @medikoo
    medikoo
    on Mar 22, 2022
    Author

    I've just looked more closely, and it appears only to Node.js as installed through snap dependency manager.

    This probably should be coined as Ubuntu's Snap bug

  4. VoltrexKeyva
    added
    child_processIssues and PRs related to the child_process subsystem.
    on Mar 22, 2022

  5. giner commented on Mar 2, 2023

    @giner
    giner
    on Mar 2, 2023

    Temporary workaround #37982 (comment)

  6. bnoordhuis commented on Mar 4, 2023

    @bnoordhuis
    bnoordhuis
    on Mar 4, 2023
    Member

    Closing, not a node bug.

  7. bnoordhuis
    closed this as not plannedon Mar 4, 2023
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