Warning "Unable to watch for file changes" regardless of "max_user_watches" set to 524288

[mbucas]

Bug Description:

Each time I start TheiaIDE, I get the warning message Unable to watch for file changes in this large workspace. Please follow the instructions link to resolve this issue.

I've applied the instructions to increase fs.inotify.max_user_watches=524288 and it's effective:

$ cat /proc/sys/fs/inotify/max_user_watches
524288

My workspace contains 2808 files and 823 folders (including .git).

Please note that my workspace is stored on NFS4.

Steps to Reproduce:

1. Open TheiaIDE
2. Open small workspace
3. The following warning message appears: Unable to watch for file changes in this large workspace. Please follow the instructions link to resolve this issue.

Additional Information

• Operating System: Gentoo Linux, with Linux Kernel 6.12.41
• Theia Version: Eclipse Theia IDE, Version 1.66.200

Both NFS Server and NFS Client are Gentoo Linux using the same version of NFS4 = net-fs/nfs-utils-2.7.1-r1 and Linux Kernel 6.12.41.

[msujew]

Hey, thanks for the report. Looks similar to #16743. I would assume our watcher library has some issues on Linux. Quick question @mbucas can you try reproducing this with VSCode or VSCodium? They are using the same library as we are - just to make sure we're the issue and it's not an upstream issue.

[mbucas]

I've opened the same folders into a new workspace in VSCode. There's no warning from VSCode either when creating the workspace or reopening it.

I didn't try to increase fs.inotify.max_user_instances or fs.inotify.max_queued_events.
Is it necessary ?

VSCode version
Version : 1.107.0
Validation : 618725e67565b290ba4da6fe2d29f8fa1d4e3622
Date : 2025-12-10T07:43:47.883Z
Electron : 39.2.3
ElectronBuildId : 12895514
Chromium : 142.0.7444.175
Node.js : 22.21.1
V8 : 14.2.231.21-electron.0
Système d’exploitation : Linux x64 6.12.41-gentoo-x86_64