[turbopack + prisma] TypeError: The "path" argument must be of type string. Received undefined

[DiPSoMaNiE]

Link to the code that reproduces this issue

https://github.com/DiPSoMaNiE/next-canary-prisma-issue

To Reproduce

1. Clone https://github.com/DiPSoMaNiE/next-canary-prisma-issue
2. Run bun install
3. Run prisma generate
4. Run bun dev
5. Go to http://localhost:3000 and see error

Current vs. Expected behavior

This error occurs when:

• using [email protected] or above (works on 15.2.0-canary.39 and below)
• using next dev --turbopack (works with next dev or next build which use webpack)
• using custom output path in the generator block of schema.prisma

To make it work:

1. Comment the output = "../generated" line in prisma/schema.prisma
2. Run prisma generate
3. Change import { PrismaClient } from '../generated' to import { PrismaClient } from '@prisma/client' in src/db.ts
4. Run bun dev
5. Go to http://localhost:3000 and see it works

Everything should work as expected with a custom output path for the generated PrismaClient.

Provide environment information

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.3.0: Thu Jan  2 20:24:22 PST 2025; root:xnu-11215.81.4~3/RELEASE_ARM64_T6041
  Available memory (MB): 49152
  Available CPU cores: 12
Binaries:
  Node: 22.14.0
  npm: 10.9.2
  Yarn: N/A
  pnpm: N/A
Relevant Packages:
  next: 15.2.0-canary.74 // Latest available version is detected (15.2.0-canary.74).
  eslint-config-next: 15.2.0-canary.74
  react: 19.0.0
  react-dom: 19.0.0
  typescript: 5.7.3
Next.js Config:
  output: N/A

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

Turbopack

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

next dev (local)

Additional context

prisma                  : 6.4.1
@prisma/client          : 6.4.1
Computed binaryTarget   : darwin-arm64
Operating System        : darwin
Architecture            : arm64
Node.js                 : v22.14.0
TypeScript              : 5.7.3
Query Engine (Node-API) : libquery-engine a9055b89e58b4b5bfb59600785423b1db3d0e75d (at node_modules/@prisma/engines/libquery_engine-darwin-arm64.dylib.node)
Schema Engine           : schema-engine-cli a9055b89e58b4b5bfb59600785423b1db3d0e75d (at node_modules/@prisma/engines/schema-engine-darwin-arm64)
Schema Wasm             : @prisma/prisma-schema-wasm 6.4.0-29.a9055b89e58b4b5bfb59600785423b1db3d0e75d
Default Engines Hash    : a9055b89e58b4b5bfb59600785423b1db3d0e75d
Studio                  : 0.509.0

[davecarlson]

Confirmed this also happens in the stable 15.2.0 next release

TypeError: The "path" argument must be of type string. Received undefined
@api:dev:     at [project]/packages/database/prisma/client/runtime/library.js [app-route] (ecmascript) (../../packages/database/prisma/client/runtime/library.js:6:1430)
@api:dev:     at [project]/packages/database/prisma/client/index.js [app-route] (ecmascript) (../../packages/database/prisma/client/index.js:26:1)
@api:dev:     at [project]/apps/api/lib/db/prisma.ts [app-route] (ecmascript) (lib/db/prisma.ts:1:0)

[thomaslenaour]

Same error here. I can confirm that it works when downgrading to [email protected].

[rburgt]

Same behaviour with the @google-cloud/logging-winston package

import { LoggingWinston } from '@google-cloud/logging-winston';

Will also throw the [turbopack] TypeError: The "path" argument must be of type string. Received undefined error

[davecarlson]

for reference, we have our database as a package, and load it like thus:

import { PrismaClient } from "@company/database";

const globalForPrisma = global as unknown as {
  prisma: PrismaClient | undefined;
};

export const prisma = globalForPrisma.prisma ?? new PrismaClient({});

if (process.env.NODE_ENV !== "production") globalForPrisma.prisma = prisma;

export default prisma;

[dikaioai]

We got the same error, using turborepo and export the db as package, same as @davecarlson

[DiPSoMaNiE]

We got the same error, using turborepo and export the db as package, same as @davecarlson

Did not mention it but I also have the database as a package within a monorepo using Turborepo, which is why I use a custom output path to manage multiple database packages. However, I have simplified the reproduction case as it is not directly related to the issue.

If you are only working with a single database in your monorepo, a quick workaround would be to avoid using a custom output path for the generated PrismaClient and instead re-export it from @prisma/client.

[jericopulvera]

related to this issue as well. boxyhq/jackson#3657 (comment)

[aramikuto]

I'm also encountering this error when trying to import @google-cloud/pubsub:

import { PubSub } from "@google-cloud/pubsub"

The issue seems to be that __dirname is undefined when using Turbopack. I tested this in a Server Component with the following code:

console.log("__dirname", __dirname)

With Webpack, the directory containing the file is correctly printed. However, when using Turbopack, __dirname is undefined.

__dirname undefined

[luiscaceresd]

I also got the same error after trying to upgrade to Nextjs 15.2. Using turborepo and prisma as a package

[AndreyMay]

same issue after upgrading to 15.2, prisma as a separate package in monorepo with custom output path

[holoiii]

seeing same thing after 15.2 upgrade with import { SecretManagerServiceClient } from '@google-cloud/secret-manager';, seeing this error: TypeError: The "path" argument must be of type string. Received undefined

EDIT: running next dev works, and next dev --turbo does not

[toescapegoats]

seeing same thing after 15.2 upgrade with import { SecretManagerServiceClient } from '@google-cloud/secret-manager';, seeing this error: TypeError: The "path" argument must be of type string. Received undefined

EDIT: running next dev works, and next dev --turbo does not

removing the turbo flag works. makes you appreciate how quick the thing is :(