next.js: Compilation time extremely slow (Next > 12.0.9)

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 20.6.0: Tue Feb 22 21:10:42 PST 2022; root:xnu-7195.141.26~1/RELEASE_ARM64_T8101
Binaries:
  Node: 16.14.2
  npm: 8.5.0
  Yarn: 1.22.18
  pnpm: N/A
Relevant packages:
  next: 12.2.3-canary.4
  eslint-config-next: 11.1.3-canary.7
  react: 17.0.2
  react-dom: 17.0.2

What browser are you using? (if relevant)

No response

How are you deploying your application? (if relevant)

No response

Describe the Bug

After updating the next package from version 12.0.9 to 12.2.0 and above, the next dev compilation time extremely slow. I tried to use compilation with SWC and with babel, the result is the same.

nextjs 12.0.9: compiled client and server successfully in 3.4s (577 modules) trace: https://gist.github.com/R1ZEN/2d032dba11947ac3b48ecfe9a4e1008d

nextjs 12.2.0: compiled client and server successfully in 46.8s (667 modules) trace: https://gist.github.com/R1ZEN/36445c707eb0e50a58cccd05af2ac19f

Expected Behavior

Compilation time would be the same or faster

Link to reproduction

I don’t have a reproduction that I can share at the moment

To Reproduce

I don’t have a reproduction that I can share at the moment, but might have some time to come up with one.

About this issue

Original URL
State: closed
Created 2 years ago
Comments: 18 (5 by maintainers)

Most upvoted comments

I noticed the exact same thing running dev now. I upgraded from 12.1.5 to 12.2.5, I now see two " compiled client and server successfully", the second one much MUCH slower than the first – we are talking more than x50 to x100 times slower, almost 2 minutes, my build takes only about 7 seconds in comparison.

@balazsorban44 This is also on MacOS. More specifically, MacOS 12.3.1 (Monterey) with a MacBook Pro (16-inch, 2021) M1 Max.

Essentially the exact same thing as reported in Why does it compile twice? (second time always much slower) · Discussion #39901 · vercel/next.js

event - compiled client and server successfully in 241 ms (193 modules)
wait  - compiling...
event - compiled client and server successfully in 113s (193 modules)

UPDATE: I downgraded and locked to 12.2.4 and this slowdown is gone, so this “issue” seems to have been introduced in 12.2.5

sebastienbarre on Sep 6, 2022

@ijjk Thanks, this is solving the issue for me

sebastienbarre on Sep 12, 2022

The issue has been identified by a user and linked to a recent PR, see my comment here. Feel free to share your experience as well. Hopefully the Next.js people can provide a workaround.

sebastienbarre on Sep 9, 2022

@balazsorban44, I added you to a repo where the issue is consistently reproduced.

R1ZEN on Jul 14, 2022