1. Could you please first post your question on stack overflow before you post here. Our issue template clearly encourages submitters to submit their questions/support there so that you have more accessible support. When you have submitted the question to stackoverflow, please provide the link there for easier access.
2. Could you please provide your full webpack configuration.

Since I think it's a possible issue I think this is the appropriate place because it might be an issue.: Full webpack config:

var debug = process.env.NODE_ENV !== 'production';
var path = require('path');
var webpack = require('webpack');

module.exports = {
  context: path.join(__dirname, '/src'),
  devtool: debug ? 'inline-sourcemap' : null,
  entry: './js-src/scripts.js',
  watch: true,
  module: {
    loaders: [
      {
        test: /.js?$/,
        exclude: /(node_modules)|(bower_components)/,
        loader: 'babel-loader',
        query: {
          presets: ['react', 'es2015', 'stage-0']
        }
      }
    ]
  },
  output: {
    path: path.join(__dirname, '/src/wwwroot/static/js'),
    filename: 'scripts.min.js'
  },
  plugins: debug ? [] : [
    new webpack.optimize.DedupePlugin(),
    new webpack.optimize.OccurenceOrderPlugin(),
    new webpack.optimize.UglifyJsPlugin({ mangle: false, sourcemap: false }),
  ],
};

Thanks!

OS: Windows 10 Anniversary Update and webpack is running in Windows Subsystem for Linux(The new bash on Ubuntu)

Probably chokidar has an issue with this...

Their issue list has a few maybe related things. @mastrauckas is there any additional details that you think might be beneficial that we (you could also as well) could submit to @paulmillr?

@TheLarkInn I have no additional information. Should I just put a ticket on their issue list and refer back to this ticket?

@mastercactapus I would be glad to help you (i've created chokidar). Are you able to set up a demo git repo that makes it easy to replicate the issue?

@paulmillr I can pull down any demo you want me too from git and run it. I might not be able to do it until tomorrow though.

@paulmillr thank you very much!!

@mastrauckas I think you have a typo
devtool: debug ? 'inline-sourcemap' : null,
should be
devtool: debug ? 'inline-source-map' : null,

@rafde Thanks for noticing that. I'll fix that tonight and see if it fixes the issue.

@rafde That didn't fix the issue. @paulmillr what did you want me to demo?

Would be great to have a demo repository where i'll be able to reproduce the issue simply without hassle and messing with configs.

@paulmillr FWIW, I experience the exact same thing on a number of webpack projects in Windows Subsystem for Linux, which have wildly varying configs. Therefore I'm not sure prepping any particular repo will help.

All that said, I share Sokra's hunch that this is either in chokidar or simply a core bug in this fancy new Windows feature. So I cloned chokidar, ran tests, got 19 passes and 76 failures (gist: https://gist.github.com/eteeselink/0c7394eab588d0851d8633cc0ade7c3f). Running the same tests on plain windows gives 0 test failures. Node 6.5.0 on both "platforms". Removed node_modules and re-did npm install before running tests on either system.

@paulmillr like @eteeselink said it might be an issue in the Windows Subsystem for Linux,. Here is a demo project https://github.com/mastrauckas/webpack-issue that is having the issue. I you need me to do anything else please let me know.

What about webpack tests? Does everything pass on the subsystem?

@paulmillr here is the result of running npm test for webpack.

@paulmillr here is also the result of running npm test on chokidar

68 failing tests for webpack.

Basically this means Windows subsystem for Linux is broken and shitty. I'll see what we can do here but a more robust solution would be to cease using it until Windows developers would fix all issues.

@paulmillr that's a perfectly valid solution for me, FWIW. WSL is beta so some incompatibilities are to be expected, i guess.

I just discovered it's a known bug in WSL: microsoft/WSL#216. If I were @sokra I'd close this bug until MS fixes inotify.

For people who find this webpack issue, the issue linked above lets you vote on this on UserVoice: https://wpdev.uservoice.com/forums/266908-command-prompt-console-bash-on-ubuntu-on-windo/suggestions/13469097-support-for-filesystem-watchers-like-inotify

I'm going to reply to the bug @eteeselink put a like to.

microsoft/WSL#216 has been closed

I've unistalled Bash on Windows 10 and webpack --watch still isn't working. Even with a very simple config like:

module.exports = {
    entry: './entry.js',
    output: {
        path: __dirname,
        filename: "bundle.js"
    }
};

Path to project is d:\_WWW\!_serwer_root\_test\webpack (if that is important). And entry.js just contains:

console.log('123');

Nevermind... The problem was the ! in the directory name :-/

Moved to webpack/watchpack#43.

Try this workaround:

Add this to your webpack configuration file:

    watchOptions: {
        poll: true
    },

watchOptions: {
poll: true
}

Thank you. This solution works for me.

I am on webpack 3, and I have poll option enabled, still Webpack picks up first few writes and then doesn't do that. I have tried saving the files via emacs and atom.

I have similar problem on Linux Mint 18.2. After fix inotify issue works fun :)

@lahdo thank you!

@lahdo I know, It's a ghost thread, but still - thank you, I've really struggled with this issue!

@lahdo thank you too, saved my day, literally!

For anyone stumbling upon this when using the node API, having

watchOptions: {
  poll: true
}

In the webpack config didn't work for me, I had to feed it into the compiler.watch function, not sure if this is intended.

const webpack = require('webpack');

const compiler = webpack({
  // these options do not seem to effect compiler.watch
  watchOptions: { 
    poll: true,
  },
});

const watching = compiler.watch({
  poll: true // this works
}, (err, stats) => { // Stats Object
  console.log(stats);
});

For googlers,
On wsl 2 you have to set poll, poll: 1000 worked for me.

This just happened to me (Putting it here because this is where it led me).
The compilation starts and finishes without any error, but it does not continue to watch for changes.
It acts as if watch is disabled.

My webpack.config.js is:

module.exports = () => ({
    entry: path.resolve(__dirname, 'src/index.ts'),
    mode: NODE_ENV,
    watch: true,
    target: 'node',
...
// rest of config (uninportant I think)
...
}

And I am running webpack via NODE_ENV=development webpack

I found the problem in my case is combination of

"webpack": "^4.44.2",
"webpack-cli": "^4.0.0",

If I change webpack-cli to version "^3.3.12" and update my deps, then everything works as expected.
Don't know why this is, but I hope it can help somebody solving the problem for themselves.
Also should mention that I am using:

yarn version - 1.22.4
node version - v14.13.0

@zatloeri Please create reproducible test repo and open an issue in webpack-cli

I had this problem, just updated webpack-cli from 4.0.0 to 4.1.0 and it fixed it!

@lahdo Thank you so much. It works.
Here is part of my Webpack setting.

module.exports = {
  watchOptions: {
    ignored: /node_modules/,
    poll: true
  }
};

• "webpack": "4.31.0",
• "webpack-cli": "3.3.2",
• "webpack-dev-server": "3.10.3"
• WSL 2
• Distributor ID: Ubuntu
• Description: Ubuntu 18.04.5 LTS
• Release: 18.04
• Codename: bionic
  FYI webpack watch option
  https://webpack.js.org/configuration/watch/#watchoptionspoll
  However, but I still don't understand that I don't have to set this option when I use Windows.
  If someone can explain, I will appreciate it.
  Thanks.