Using script-loader seems to lead to a different [chunkhash] being generated each time

[jakub-g]

Hello,

First of all, I know that [chunkhash] is not the best idea for long term caching, and it's better to use a plugin that creates content-hash, which we will probably do very soon.
Nevertheless I wanted to report the issue, even if only to help some other people who are investigating similar issues.

---

So, we're using webpack 3.x for now, and we have two external scripts, let's call them foo and bar that are loaded through script-loader 0.7.1 like this:

  loadFooLib() {
    return import(/* webpackChunkName: 'foobar' */ 'script-loader!foo')
  },

(with foo$: 'html/vendor/foo/Foo' in webpack resolve config).

When we run the build twice after some time, without any code change in foo or bar (for example, a non-code commit), this often* results in the chunkhash change for foo and bar (the chunks that go through script-loader), and no output change for the other chunks -- and this in turn means that the manifest chunk has to be regenerated as well.

*often = not always, and it's happening a lot on our Linux build machines, but I could not reproduce so far on Windows

Looking at the code, things look very simple and there seems to be no obvious reason for script-loader to generate different chunkhash each time.

@sokra Do you have any ideas? Is this kind of issue more likely to be on the plugin side, or webpack side?

[michael-ciniawsky]

It's a bit 'old' but maybe it helps https://medium.com/webpack/predictable-long-term-caching-with-webpack-d3eee1d3fa31, otherwise I'm sry but it is very hard to exactly tell where/what in your application currently causes the [chunkhash] to change

[jakub-g]

FWIW we've migrated do webpack 4 and contenthash (and followed all other best practices to get reproducible builds) and this still happens (only for stuff loaded with script-loader).
Will need to deep dive into it to figure out what's exactly happening.

[jakub-g]

Update: from what I've noticed in the recent weeks, the issue actually happens also for some new chunks in our project that are not loaded via script-loader. The issue is not script-loader then (probably).

webpack/webpack#7179 (comment)

[onlybye]

Update: from what I've noticed in the recent weeks, the issue actually happens also for some new chunks in our project that are not loaded via script-loader. The issue is not script-loader then (probably).

webpack/webpack#7179 (comment)
@jakub-g we have also met this problem, have you solved?

[jakub-g]

we have also met this problem, have you solved?

nope, not yet unfortunately

[jakub-g]

@onlybye see #49 #60 and https://medium.com/@the_teacher/webpack-different-assets-hashes-on-different-machines-the-problem-the-solution-ec6383983b99