Next.js Cache not working with CircleCI

Link to the code that reproduces this issue

https://github.com/DoctrineLegal/nextjs-cache-issue/blob/master/README.md

To Reproduce

1. Trigger a build on CircleCI
2. Cache it's .next directory
3. Re-trigger a build on CircleCI with a hot cache
4. See that next.js is not using the cache

Current vs. Expected behavior

Current behavior: https://app.circleci.com/pipelines/github/DoctrineLegal/nextjs-cache-issue/1/workflows/745158ac-1c40-448e-9083-391e90cb0938/jobs/1

CircleCI is not using the cache. And consistently taking the same time to build.

Expected Behavior: https://app.circleci.com/pipelines/github/DoctrineLegal/nextjs-cache-issue/1/workflows/745158ac-1c40-448e-9083-391e90cb0938/jobs/1

CircleCI should use the cache as specified here : https://nextjs.org/docs/pages/building-your-application/deploying/ci-build-caching#circleci

When forcing the cache dir it actually works.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.0.0: Tue Sep 24 23:38:45 PDT 2024; root:xnu-11215.1.12~1/RELEASE_ARM64_T8122
  Available memory (MB): 16384
  Available CPU cores: 8
Binaries:
  Node: 22.4.1
  npm: 10.8.1
  Yarn: 1.22.22
  pnpm: 9.15.0
Relevant Packages:
  next: 15.0.4-canary.46 // There is a newer canary version (15.0.4-canary.48) available, please upgrade! 
  eslint-config-next: 15.0.2
  react: 19.0.0-rc-02c0e824-20241028
  react-dom: 19.0.0-rc-02c0e824-20241028
  typescript: 5.6.3
Next.js Config:
  output: N/A
 ⚠ There is a newer canary version (15.0.4-canary.48) available, please upgrade! 
   Please try the latest canary version (`npm install next@canary`) to confirm the issue still exists before creating a new issue.
   Read more - https://nextjs.org/docs/messages/opening-an-issue

Which area(s) are affected? (Select all that apply)

Performance, Webpack

Which stage(s) are affected? (Select all that apply)

next build (local)

Additional context

CircleCI is indeed running on docker with a cgroup container docker : https://github.com/vercel/next.js/blob/canary/packages/next/src/compiled/is-docker/index.js and found as docker from this file.

I believe this PR : https://github.com/vercel/next.js/pull/70516 from @shuding introduced the issue.

As a side note : CircleCI is currently rolling out new containers that will not be subject to this issue : https://discuss.circleci.com/t/docker-executor-infrastructure-upgrade/52282

Start with the reproduction repository's README and the CircleCI workflow described in the issue, then inspect packages/next/src/compiled/is-docker/index.js and PR #70516. Reproduce the cache behavior with a hot CircleCI cache and compare it with the configuration that forces the cache directory. Done means the documented CircleCI cache is used reliably without forcing the directory.