child_process.spawn is considerably slower in Node 12+

[ion-dev]

Version

Node v12+

Platform

MacOS (Big Sur)

Summary

We've discovered an issue with Electron 12 and above (Node 14 and above), where spawning a child_process takes considerably longer than Electron 11 and lower (Node 12 and lower).

The issue appears to be related to the Node version - Here's an example app, with instructions, to demonstrate:
https://github.com/dev-manager-uk/spawn-delay

After running the app initially, you'll notice the spawn function takes ~10ms.

After upgrading Electron to 12 or higher, you'll notice the spawn function takes ~500ms!

What's changed to cause this and can anything be done about it?

Thanks!

-- UPDATE --

This bug only occurs on macOS running Big Sur AND only with Electron 12+. I tested on Windows 10 and macOS running Mojave and could not replicate. Electron 11 and lower are also fine.

To summarise, this delay only occurs on macOS running Big Sur with Electron 12 and greater.

[RaisinTen]

Are you sure that this isn't macOS specific? These issues might be related:

• child_process spawn locks up renderer for 300 - 3000ms on signed app on macOS Big Sur electron/electron#26143
• uv_spawn is slow when parent process allocates mmap with MAP_JIT flag libuv/libuv#3050

[dreamthen]

My mac platform version is monterey, and there is still a problem of 800ms slow.

[dreamthen]

The result is in the electron of running the same code on version 11 and version 12+ is that version 12+ is 800 ms slower.

[RaisinTen]

Electron has already backported the libuv fix in electron/electron#33337 and updating libuv to v1.44.1 should fix the problem in Node.js and there is already a PR doing that here - #42340.

[santigimeno]

#42340 already landed