[BUG] npm not handling process signals

Is there an existing issue for this?

I have searched the existing issues

NOTE: I originally posted this issue on nodejs/node but was redirected here.

This issue exists in the latest npm version

I am using the latest npm

Current Behavior

npm doesn't handle SIGTERM like it used to. I noticed this issue specifically when updating node from v20.2.0 to v20.3.0 (npm 9.6.7 to 9.8.1).

Expected Behavior

Expected that the below program exits with code 0 (i.e., npm is aborted by the signal and the script handles the signal as well)

Steps To Reproduce

The below script sends a SIGTERM to the npm process that spawned it. Run npm run test with:

In package.json

    {
      "name": "test",
      "version": "0.0.0",
      "type": "module",
      "scripts": {
        "test": "node test.js"
      }
    }

In test.js

    import { execSync } from 'child_process';

    process.on('SIGTERM', () => {
        console.log('Received SIGTERM. Exiting...');
        process.exit(0);
    });

    const output = execSync('ps -e | grep npm').toString().split(/\s+/).filter(Boolean);
    const pid = Number(output[0]);
    process.kill(pid)

    setTimeout(() => {
        console.log('Fatal: Signal was not received. Exiting... ');
        process.exit(1)
    }, 2000);

Environment

npm: 9.8.0
Node.js: v20.5.0
OS Name: Linux nixos 5.15.93 x86_64 GNU/Linux
System Model Name:
npm config:

; node bin location = /nix/store/1gnvy2dhh311c900hzyw6ppjdhnir2s5-nodejs-20.5.0/bin/node
; node version = v20.5.0
; npm local prefix = /build
; npm version = 9.8.0
; cwd = /build
; HOME = /homeless-shelter
; Run `npm config ls -l` to show all defaults.

@ryanrasti

@ryanrasti I'm getting this same behavior in npm v9.6.7. Can you verify what npm version was working?

In my case package.json scripts that were receiving the signals fine in npm v8.19.4 (node v16.20.1) stopped working when upgrading directly to npm v9.6.7 (node v18.17.0).

There is a possibly identical issue that was opened at #6547, but no triage occurred in the month since it was opened.

This may be caused by a change made in npm/run-script#142. There were no tests associated with the changed behavior. Maybe an issue needs opened in that repository?

cc: @nlf, @wraithgar

@ngbrown

Indeed, good catch @ngbrown , the version that worked for me was 9.6.6 (not 9.6.7).

Indeed, this looks like a duplicate of #6547 but that bug is incorrectly tagged with Release 8.x

@nlf

How does this issue still have zero response? Very disappointing. @nlf @wraithgar

For those looking for a workaround on Linux, you can kill the entire process tree like this:

npm start &
pid=$! # root process ID
gid=$(ps -o pgid= $pid) # process group ID
kill -SIGTERM -$gid

As a bonus, you can inspect the process tree with either the root process ID or the process group ID like this:

pstree -pT $pid
ps -jH -$gid

Any news about this?

Revert Signal Handling Regression (#188)

fix: Revert Signal Handling Regression (#188)

Since npm@v10.3.0 which depends of @npm/run-script@7.0.3 (in which the regression was fixed), everything works fine for me :).
Thanks 🎉

I've faced the same issue...

I can confirm that npm version 10.3.0 does forward the signals as expected.

Update NPM to fix npm/cli#6684

I think this is still happening on Ubuntu 20.04.6 LTS with node 18.20.0 and npm 10.5.0

We have tested 10.3.0 and 10.5.0 on Node 21.7.3 & MacOS Sonoma and unfortunately the problem is still there.

I am able to reproduce on npm 10.3.0 and node v21.6.2, on macos 13.4

Here a small repository with another example that reproduces the problem: https://github.com/skyrpex/npm-scripts-sigint-problem.

The issue happens with npm 10.5.2.

I have created a demo repo to showcase the bug. The repo verifies that this only happens in versions of NPM >=9.6.7 <10.3.0. If you experience this in another version of NPM, please create a repo which shows the error happening.

https://github.com/DesignByOnyx/npm-signals-bug

Any news?

The reason for the inconsistency, where some report the signals are forwarded successfully while others do not, is: The inconsistent part is because of the use of sh in @npmcli/promise-spawn.

The signal is forwarded correctly in npm, but may be ignored by sh. I don't test very much, but at least in node:20-alpine the signal is forwarded to the underlying script but in node:20-slim (debian) not. And also, using Ctrl + C in the terminal will always work as it doesn't rely on signal forwarding only but also uses the job control to send signals to the child process)

And before waiting for a fix, using something like "start": "exec node index.js" can work

The reason for the inconsistency, where some report the signals are forwarded successfully while others do not, is: The inconsistent part is because of the use of sh in @npmcli/promise-spawn.

The signal is forwarded correctly in npm, but may be ignored by sh. I don't test very much, but at least in node:20-alpine the signal is forwarded to the underlying script but in node:20-slim (debian) not. And also, using Ctrl + C in the terminal will always work as it doesn't rely on signal forwarding only but also uses the job control to send signals to the child process)

Seeing the same behavior, the bug persists in node:22, but node:22-alpine forwards the signal correctly.

It has something to do with the default shell in your image. node:22 image defaults to using dash whereas bash or busybox with node:22-alpine does an implicit exec-like optimization that replaces the shell. This screenshot shows it pretty clearly, explaining why the signal might not be getting to our node apps.

The scripts with npm in node:22 have 2 subprocess "hops", one from npm itself and another from the shell. Whereas with bash as default (/bin/sh) shell it will only create one subprocess which npm will relay the signal to.

fix(ci): isolate chaos and demo into separate jobs; assert mock fresh…

fix(scripts): the cleanup traps stop killing the messenger and start …

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[BUG] npm not handling process signals #6684

Is there an existing issue for this?

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[BUG] npm not handling process signals #6684

Description

Is there an existing issue for this?

This issue exists in the latest npm version

Current Behavior

Expected Behavior

Steps To Reproduce

Environment

Activity

ngbrown commented on Jul 28, 2023

ryanrasti commented on Jul 29, 2023

thejohnfreeman commented on Aug 21, 2023

dmaizel commented on Oct 18, 2023

tdislay commented on Feb 7, 2024

mahnunchik commented on Feb 19, 2024

DesignByOnyx commented on Mar 6, 2024

grcode123 commented on Mar 28, 2024

Dzieni commented on Apr 24, 2024

ekeren commented on Apr 24, 2024

skyrpex commented on Apr 24, 2024

DesignByOnyx commented on Apr 24, 2024

mahnunchik commented on Dec 7, 2024

ImSingee commented on Jan 2, 2025

ImSingee commented on Jan 2, 2025

filip-jaksic commented on May 14, 2025

jtomlin12 commented on Nov 25, 2025

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