Can anyone tell me what this error means? And how to fix it?

pants package path/to/folder:main
16:34:08.67 [ERROR] 1 Exception encountered:

Engine traceback:
  in `package` goal

IntrinsicError: Failed to watch filesystem for `/path/to`: Error { kind: MaxFilesWatch, paths: ["/path/to"] }

Sorry for the trouble. What platform are you using pants on?

linux (ubuntu). This happens for one user but not for others. when that user tried packaging other code they get the same error. When any other user tries it, it's not a problem.

Chances are this is a Linux issue and not something with Pants - here are some tips on dealing with system-level watcher limits: https://stackoverflow.com/questions/53930305/nodemon-error-system-limit-for-number-of-file-watchers-reached And a helper from Pants docs: https://www.pantsbuild.org/2.18/docs/using-pants/troubleshooting-common-issues#no-space-left-on-device-error-while-watching-files

What makes you think this is a linux issue not a pants issue?

This:

Error { kind: MaxFilesWatch,

yh those aren't helpful I'm afraid. I don't think it's clear why this issue is happening for one user and not for others. I'm not convinced that we can know it's linux and not pants.

That seems like a ulimit issue then? It’s possible that one user has a lower ulimit than others which is causing you to run out of files: https://docs.revenera.com/fnci6132/Content/helplibrary/Setting_the_Open_File_Limit__Linux_Unix_.html

yh ok, we've resolved it now, it was solved with:

sudo sysctl -w fs.inotify.max_user_watches=100000