Minimal reproduction for Next.js logging failed to read input source map for pnpm workspace dependencies whose source map files exist.

pnpm install
pnpm build

The build succeeds, but Next logs errors like:

ERROR failed to read input source map: failed to find input source map file "index.js.map" in "node_modules/.pnpm/@[email protected][email protected]/node_modules/@ai-sdk/provider-utils/dist/index.js" file as either "node_modules/.pnpm/@[email protected][email protected]/node_modules/@ai-sdk/provider-utils/dist/index.js.map" or with appended .map
    at crates/swc/src/lib.rs:398

ERROR failed to read input source map: failed to find input source map file "index.js.map" in "node_modules/.pnpm/@[email protected]/node_modules/@workflow/serde/dist/index.js" file as either "node_modules/.pnpm/@[email protected]/node_modules/@workflow/serde/dist/index.js.map" or with appended .map
    at crates/swc/src/lib.rs:398

Next should not log source-map read errors when the referenced package map files exist.

The package map files exist in the workspace root pnpm virtual store:

test -f node_modules/.pnpm/@[email protected][email protected]/node_modules/@ai-sdk/provider-utils/dist/index.js.map
test -f node_modules/.pnpm/@[email protected]/node_modules/@workflow/serde/dist/index.js.map

But the app build runs from apps/web, and the error appears to resolve node_modules/.pnpm/... relative to the app directory instead of the workspace root where pnpm created the virtual store.

• A plain Next app importing AI SDK did not reproduce this. The error appears when workflow/next compiles a workflow that imports AI SDK packages.
• The workflow step imports ai and @ai-sdk/openai, but it does not call a model, so no API key is required.
• Related issues:
  • vercel/next.js#90910
  • vercel/workflow#338

• Next.js: 16.2.9
• React: 19.2.7
• pnpm: 11.7.0
• ai: 7.0.4
• @ai-sdk/openai: 4.0.2
• workflow: 5.0.0-beta.25