`@prisma/client@x is not compatible with prisma2@y. Their versions need to be equal.`, generates anyway

C:\Users\Jan\Documents\throwaway\1496
λ npx prisma2@alpha generate
⚠️ @prisma/client@2.0.0-preview021 is not compatible with prisma2@2.0.0-alpha.735. Their versions need to be equal.
Generated Prisma Client to .\node_modules\@prisma\client
Done in 13.52s

Is this a warning or an error? The further output indicates it generated anyway. Should it do that or should it really fail?

[janpio]

Decision: We talked it through, and right now there is no reason to have this warning in the first place because CLI and Client can currently be used in any combination. In the future we might want to have a versioning system for the internal API, which could lead to errors on mismatch.

[janpio]

1. You’re going to assume @prisma/photon@2.0.0-preview018.2 and prisma2@2.0.0-preview018.2 are the same package when you first scan over it. The names are too similar. We should make this more clear that the Prisma Client depends on a particular version of the CLI

The error message should probably make this more explicit by not just printing the package names, but annotating them in some way.

2. We should call out that this is a warning and you may not need to deal with this. This is 5 minutes of focus lost on something that’s not building my product.

In the comments above we are discussing if a warning is actually enough here or if this should/has to be an error.

Lastly a matter of opinion: this communicates to me that Prisma is going to regularly make breaking changes to the Prisma Client runtime, so Prisma requires you to keep these packages in lockstep.

This makes me sad. We should know when we’re going to make breaking changes and show this warning at those transition marks (with custom messages), not every single time.

Valid point, please open a new issue for this so this does not get lost.