Error: EMFILE: too many open files, watch

Have you checked your total limit of how many open files can you have at maximum?

Did You make any changes to the watchers configuration?

No. I didn’t make any changes. Apart from changing --watch-stdin with --watch.

Did You change this for Webpack 5?

Maybe like this?

    node: [
      "node_modules/webpack/bin/webpack.js",
      "--mode",
      "development",
      "--watch",
      "--watch-options-stdin",
      cd: Path.expand("../assets", __DIR__)
    ]

Hmmm. I am not familiar with this --watch-options-stdin. The info I saw - somewhere - strongly implied I should drop --watch-stdin.

e.g. the top two google results for watch-stdin:

https://github.com/revelrylabs/revelry_phoenix_app_template/issues/811
https://github.com/phoenixframework/phoenix/issues/4020

Which links to the fix:

https://github.com/ruudk/phoenix/commit/67799f647dda4cb8b9275053aa8e1fc0d2ce7303

From the docs:for watch-options-stdin:

Stop watching when stdin stream has ended

Apparently I have 90 copies of webpack running. Oh, that would explain it.

Will make the change, kill my webpacks, and hopefully that will fix this.

Thanks!

It would be good if there was an authoritative source somewhere of correct changes required to the webpack stuff from the standard phoenix template.

See also Webpack error after upgrading mini-css-extract-plugin@1.6.2 - #3 by derek-zhou for an example of just another problem this has caused me.

You might find reference here…

https://github.com/phoenixframework/phoenix/pull/4054

Good point. I guess I should compare my assets directory with the values from the git source at phoenix/installer/templates/phx_assets at main · phoenixframework/phoenix · GitHub

Sounds like Pheonix is now switching to using esbuild. https://twitter.com/josevalim/status/1417017859847475201