[NEXT-1139] [BUG] Very long dev builds 50 times slower

[OlegLustenko]

Verify canary release

• I verified that the issue exists in the latest Next.js canary release

Provide environment information

Operating System:
      Platform: darwin
      Arch: arm64
      Version: Darwin Kernel Version 22.3.0: Mon Jan 30 20:38:37 PST 2023; root:xnu-8792.81.3~2/RELEASE_ARM64_T6000
    Binaries:
      Node: 18.14.0
      npm: 9.4.1
      Yarn: 1.22.19
      pnpm: 7.25.0
    Relevant packages:
      next: 13.2.4-canary.5
      eslint-config-next: 13.1.6
      react: 18.2.0
      react-dom: 18.2.0

Which area(s) of Next.js are affected? (leave empty if unsure)

No response

Link to the code that reproduces this issue

can I add this later?

To Reproduce

Our application heavily using rewrites, it might be the case

• Update to latest next.js
• npm run dev, track compilation time

Describe the Bug

Compilation takes too much time

13.1.6

13.2.2+, also tested on canary builds

Expected Behavior

It takes less or the same amount of time

Which browser are you using? (if relevant)

No response

How are you deploying your application? (if relevant)

No response

_NEXT-1139

[red1]

I had a similar issue on a Mac Book Pro M2, I had to deactivate SWC in next.config.js

[OlegLustenko]

@red1 thanks for reporting! it's awesome! It helps to allocate the problem space a lot

[zdraffko]

I am experiencing the same issue with Next.js 13 on Windows 11.

[ijjk]

Hi, could you try removing any previous changes to next.config.js and only set experimental: { swcFileReading: false } to confirm whether it's related to that or not?

[OlegLustenko]

@ijjk oh wow! Thanks for the quick response, and even more, it helped!

Can I treat it as a recommendation as-of-now?

[ijjk]

For now yes, we will investigate further!

[OlegLustenko]

More info after fresh npm install it still reproduced even with a flag

[OlegLustenko]

It still fantomly reproduced even with swcFileReading :(

It's a hard blocker for us and we have to revert back 13.1.6

[OlegLustenko]

@ijjk, do we need to add some bug tags so it's not lost visibility?

The thing is in 13.2.x versions rewrites fixed for appDir

[SilentDepth]

Facing the same issue here. I did some little experiments in my Next.js + Tailwind CSS project and found that if I use brace expansion in the middle part of paths in Tailwind CSS content option, like ./{components,pages}/**/*.jsx, then next dev will take a very long time to compile. Splitting it into several patterns (e.g. ['./components/**/*.jsx', './pages/**/*.jsx']) solves my problem.

[wh5938316]

Is there any update on this? I am experiencing a similar issue where my dev builds are very slow on my Mac Pro M1. This issue occurs when using versions of Next.js above 13.2.4, so I have had to lock my version to 13.2.4.

[wadehammes]

Not sure if related, but I am getting this now like every build and my builds are 3x longer than they use to be to Vercel:

Some times it wont happen but they are still very long build times.

Avg build for our 1700 pages use to be 9-11min, now its taking 24min. I even went in and optimized over 100 images our marketing team had uploaded to our Contentful that were huge, shaving off roughly 200MB (yikes, I know).

[timneutkens]

Hey, can you share the .next/trace file when running on the previous version and then upgrade and share the trace file for that too. Then we can at least get some insight into what's different as there is no reproduction provided.

[timneutkens]

Closing this issue to consolidate the same reports here: #48748 (comment).
Please follow the steps provided in order for us to investigate further.