SPFx Fast Serve: version mismatch. We detected the usage of SPFx 1.20, but "spfx-fast-serve-helpers" version is 1.17

[Lontkovsky]

Hi.

I'm working with @microsoft/sp-build-web version ~1.20.1 and spfx-fast-serve-helpers version ~1.17.0. However, I'm encountering a bundling issue with the following error:

SPFx Fast Serve: version mismatch. We detected the usage of SPFx 1.20, but "spfx-fast-serve-helpers" version is 1.17. Please change "spfx-fast-serve-helpers" version to ~1.20.0, delete node_modules, package-lock.json, and reinstall dependencies.

Despite multiple attempts to update the version of these dependencies to resolve the mismatch, bundling continues to fail. I've tried adjusting versions, deleting node_modules, and reinstalling dependencies, but the issue persists.

Has anyone experienced this before or have suggestions on how to resolve this version mismatch? I'm also curious if there's a known fix on the roadmap for this, as I suspect this might be addressed in future updates.

Thanks!

[s-KaiNet]

Hi, SPFx 1.20 is in beta, I haven't released fast-serve 1.20 beta yet, thus you have these errors. I can do it today, if it works with SPFx 1.20 preview. Otherwise, I have to fix fast-serve, but to my knowledge there were no breaking changes in SPFx 1.20 related to build process, that's why it should work.

[Lontkovsky]

@s-KaiNet thank you for your prompt response. If you could expedite the release of fast-serve version 1.20, it would greatly assist me in verifying the functionality of the bundling process.

[s-KaiNet]

You can install npm i spfx-fast-serve-helpers@1.20.0-beta.0 -DE, which support SPFx 1.20 preview.

[s-KaiNet]

I will close the issue, if you have any further problems, just reopen or create a new one.

[Lontkovsky]

@s-KaiNet yes, please, thanks a lot!