Downgrading from v3 yields a generate error

Bug description

When doing the upgrade to v3, I found that downgrading from v3 to v2.26 yields an error. This is super important but can be annoying for the small time where you are upgrading to v3. This happened in yarn classic monorepo with one package containing the prisma and generating it for two other packages.

$ yarn workspace my-workspace prisma generate
yarn workspace v1.22.5
yarn run v1.22.5
$ prisma generate
Prisma schema loaded from prisma/schema.prisma
Error: Could not convert engine type libqueryEngine
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
error Command failed.
Exit code: 1
Command: /Users/Sytten/.nvm/versions/node/v14.17.6/bin/node
Arguments: /usr/local/Cellar/yvm/4.1.4/versions/v1.22.5/lib/cli.js prisma-generate
Directory: /Users/Sytten/Projects/my-project/packages/my-workspace

You have to delete the node_modules (or at least the prisma folder) manually to make it work.

How to reproduce

1. Upgrade to v3
2. Run yarn
3. Downgrade to v2.26
4. Run yarn
5. Try to generate

Expected behavior

Works without issue

Environment & setup

• OS: MacOS
• Database: Postgres
• Node.js version: 14.17.6

[chaostheory]

@Sytten Thanks for the help, but unfortunately that didn’t work in my case

This is literally my entire schema.

// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema

datasource db {
  provider = "sqlite"
  url      = "file:./test.db"
}

generator client {
  provider = "prisma-client-js"
}

model Patrol {
  id              Int                         @id @default(autoincrement())

  createdAt       DateTime                    @default(now())
  lastUpdatedAt   DateTime                    @default(now())
}

My sqlite database is also empty. Everything worked fine before the installing version 3

UPDATE: downgrading back to version 2 fixes everything.

[Sytten]

My solution was to delete node_modules and it went away. Bit annoying but yeah 😕