Config file loading fails with Yarn PnP (ERR_INVALID_RETURN_PROPERTY_VALUE)

[OrlovAlexei]

Reproduction link or steps

https://github.com/OrlovAlexei/tsdown-pnp-bug-repro

git clone https://github.com/OrlovAlexei/tsdown-pnp-bug-repro

cd tsdown-pnp-bug-repro

yarn install

yarn build

What is expected?

Build succeeds and outputs files to dist/

What is actually happening?

ℹ tsdown v0.17.2 powered by rolldown v1.0.0-beta.53
ERROR TypeError [ERR_INVALID_RETURN_PROPERTY_VALUE]: Expected a string, an ArrayBuffer, or a TypedArray to be returned for the "source" from the "load" hook but got undefined.

Any additional comments?

• Happens with all config file formats: .ts, .js, .mjs, .cjs
• Environment: Node.js 22.x, Yarn 4.x with PnP mode
• Workaround: remove config file and use CLI args instead (yarn tsdown src/index.ts --format esm)
• The issue appears to be in the native config loader when used with Yarn PnP's ESM hooks

[sxzz]

It may caused by a bug of Node.js loader, since issue is fixed after upgrading Node.js to v24.

[sxzz]

Track Gugustinette/unrun#15