nextjs - ✅(Solved) Fix Unresolvable warnings on latest 15.x: "Mismatching @next/swc version" [2 pull requests, 21 comments, 21 participants]

nextjs2026-01-29 16:36:27

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vercel/next.js#89251•Fetched 2026-04-08 02:03:04

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grantbdev

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Fix Action

Fixed

Fixed by PR: fix: next upgrades and gitingore .env file (https://github.com/Festivus-Cortex/norstep4700.com/pull/27)
Fixed by PR: chore(chat): bump next from 15.5.11 to 15.5.12 to fix error (https://github.com/epam/ai-dial-chat/pull/5724)

PR fix notes

PR #27: fix: next upgrades and gitingore .env file

Repository: Festivus-Cortex/norstep4700.com
Author: Norstep
State: closed | merged: True
Link: https://github.com/Festivus-Cortex/norstep4700.com/pull/27

Description (problem / solution / changelog)

Upgrade next.js to patch known security issues and fix gitingore for .env files

Resolves #25 #26 #27 #28 #29 #30

Changed files

.gitignore (modified, +2/-2)
package.json (modified, +2/-2)
yarn.lock (modified, +230/-269)

PR #5724: chore(chat): bump next from 15.5.11 to 15.5.12 to fix error

Repository: epam/ai-dial-chat
Author: IlyaBondar
State: closed | merged: True
Link: https://github.com/epam/ai-dial-chat/pull/5724

Description (problem / solution / changelog)

Description:

bump next from 15.5.11 to 15.5.12 to fix error https://github.com/vercel/next.js/issues/89251

Checklist:

the pull request name complies with Conventional Commits
the pull request name starts with fix(<scope>):, feat(<scope>):, feature(<scope>):, chore(<scope>):, hotfix(<scope>): or e2e(<scope>):. If contains breaking changes then the pull request name must start with fix(<scope>)!:, feat(<scope>)!:, feature(<scope>)!:, chore(<scope>)!:, hotfix(<scope>)!: or e2e(<scope>)!: where <scope> is name of affected project: chat, chat-e2e, overlay, shared, sandbox-overlay, etc.
the pull request name ends with (Issue #<TICKET_ID>) (comma-separated list of issues)
I confirm that do not share any confidential information like API keys or any other secrets and private URLs

Changed files

package-lock.json (modified, +40/-40)
package.json (modified, +1/-1)

Code Example

Operating System:
  Platform: linux
  Arch: arm64
  Version: #1 SMP Fri Nov 21 10:33:45 UTC 2025
  Available memory (MB): 7837
  Available CPU cores: 12
Binaries:
  Node: 22.21.1
  npm: 10.9.4
  Yarn: 1.22.22
  pnpm: N/A
Relevant Packages:
  next: 15.5.11 // An outdated version detected (latest is 16.1.6), upgrade is highly recommended!
  eslint-config-next: N/A
  react: 19.2.3
  react-dom: 19.2.3
  typescript: 5.9.3
Next.js Config:
  output: N/A

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Link to the code that reproduces this issue

https://codesandbox.io/p/devbox/determined-sunset-6wnnlk?workspaceId=ws_R3K1XVqknhzjCa9nBvnFtd

To Reproduce

Install a version of Next 15.5 greater than 15.5.7 (15.5.11 is the latest)
Run next dev
See a warning in the terminal output like this: "Mismatching @next/swc version, detected: 15.5.7 while Next.js is on 15.5.11. Please ensure these match"

The CodeSandbox link should produce this output automatically.

Current vs. Expected behavior

I expect no warning when on the latest versions of the same major+minor version of next and @next/swc. The latest @next/swc versions for 15.5.x are 15.5.7, so there isn't a way to upgrade on 15.5.x to resolve the warning. [email protected] lists 15.5.7 as the optional dependency version for the @next/swc packages.

I believe package managers will install whatever versions are listed in the optional dependencies for next, so maybe this warning code could be removed altogether.

Provide environment information

Operating System:
  Platform: linux
  Arch: arm64
  Version: #1 SMP Fri Nov 21 10:33:45 UTC 2025
  Available memory (MB): 7837
  Available CPU cores: 12
Binaries:
  Node: 22.21.1
  npm: 10.9.4
  Yarn: 1.22.22
  pnpm: N/A
Relevant Packages:
  next: 15.5.11 // An outdated version detected (latest is 16.1.6), upgrade is highly recommended!
  eslint-config-next: N/A
  react: 19.2.3
  react-dom: 19.2.3
  typescript: 5.9.3
Next.js Config:
  output: N/A

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

SWC

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

next dev (local)

Additional context

Code that produces the warning: https://github.com/vercel/next.js/blob/f1a047fd80944ac722ab6e481e1ec077378d31fc/packages/next/src/build/swc/index.ts#L131-L139

extent analysis

TL;DR

The warning about mismatching @next/swc version can be addressed by ensuring the versions of next and @next/swc match, but since the latest @next/swc for version 15.5.x is 15.5.7, the warning might be unnecessary and could potentially be removed or ignored for now.

Guidance

Review the dependency versions installed by your package manager to confirm that @next/swc version 15.5.7 is being used with next version 15.5.11.
Consider upgrading to a newer major version of next where the @next/swc version mismatch warning might be handled differently, but be aware that this could introduce other changes.
If the warning is not causing issues, it might be safe to ignore it until a future version of next or @next/swc resolves the version mismatch warning.
Investigate if there's an open issue or discussion on the Next.js repository regarding this warning and potential plans to address it.

Example

No specific code example is provided as the issue seems related to version management rather than a code snippet fix.

Notes

The warning is triggered by a version mismatch detection in the Next.js codebase, specifically designed to ensure compatibility between next and @next/swc. However, given the constraints of the versioning, there might not be an immediate fix other than waiting for updates or ignoring the warning if it does not affect functionality.

Recommendation

Apply workaround: Ignore the warning if it does not cause any functional issues, as upgrading @next/swc beyond 15.5.7 is not currently possible within the 15.5.x series, and the warning might be removed or adjusted in future versions of Next.js.

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nextjs - ✅(Solved) Fix Unresolvable warnings on latest 15.x: "Mismatching @next/swc version" [2 pull requests, 21 comments, 21 participants]

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Fix Action

Fixed

PR fix notes

PR #27: fix: next upgrades and gitingore .env file

Description (problem / solution / changelog)

Changed files

PR #5724: chore(chat): bump next from 15.5.11 to 15.5.12 to fix error

Description (problem / solution / changelog)

Changed files

Code Example

Link to the code that reproduces this issue

To Reproduce

Current vs. Expected behavior

Provide environment information

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

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

Additional context

extent analysis

TL;DR

Guidance

Example

Notes

Recommendation

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nextjs - ✅(Solved) Fix Unresolvable warnings on latest 15.x: "Mismatching @next/swc version" [2 pull requests, 21 comments, 21 participants]

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Fix Action

Fixed

PR fix notes

PR #27: fix: next upgrades and gitingore .env file

Description (problem / solution / changelog)

Changed files

PR #5724: chore(chat): bump next from 15.5.11 to 15.5.12 to fix error

Description (problem / solution / changelog)

Changed files

Code Example

Link to the code that reproduces this issue

To Reproduce

Current vs. Expected behavior

Provide environment information

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

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

Additional context

extent analysis

TL;DR

Guidance

Example

Notes

Recommendation

Still need to ship something?

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