npm run build takes 1-2 hours to build

[clu3]

First off, thank you for everything.

I have a fairly big react app (200K locs , css excluded), and recently it takes me hours to npm run build (It used to be like 9min which was aweful as well but i could still live with it). Some change in the last few weeks, which we haven't been able to identify what because our package.json still looks fine, has increased the build time from 10m to 1-2hours, sometimes 3 on my laptop. And the build process usually runs out of memory and dies on my colleagues' machines.

We use react-router and react-loadable to split the code.

When I examine the build folder, i still have like
main.ad2ec57c.js 3.5M
main.ad2ec57c.js.map : 21M
and lots of other chunks of size 5-100K.

Can you pls point me some direction on how to go about solving this?

[gaearon]

Can you disable sourcemaps?

Put

GENERATE_SOURCEMAP=false

in your .env file and try again.

Also it would help to have more info about react-scripts version, etc.

[clu3]

Thanks @gaearon for the really quick reply
I'm running Ubuntu 16 LTS and have

"react": "^16.3.2",
"react-scripts": "^1.1.4",
node v8.1.2
npm 6.0.1

And here is my complete package.js : https://gist.github.com/clu3/d008f57f77dbff284427aa4666fb3b58

Im trying to re-build with no source map. It still looks like it's taking time. So i'll go ahead and post my comment here, hoping i'll get something figured out earlier.

Update
It's finished building, now it's like roughly 10-15min

[Timer]

This application sounds massive! With source maps disabled, there's no way we're going to squeeze more performance out of your build unless if you upgrade to the new alpha and give it a try -- it has a lot of caching on by default, but be aware it has its own set of bugs/issues which causes suboptimal bundle distribution. Stay tuned!