TS6305: Output file '/path/to/dist/index.d.ts' has not been built from source file '/path/to/src/index.ts'.

I did a little bit of digging into this and I think it’s a race condition when building.

I believe this stems from fork-ts-checker and ts-loader running in parallel. Typescript composite projects rely on the dist files being emitted and on disk, so if fork-ts-checker starts typechecking a module that ts-loader hasn’t emitted yet, the above error would likely occur. That also explains why running build a second time resolves the issue (since the older files are already on disk). This could potentially result in changes not being type-checked if on-disk files were stale.

I don’t have any concrete evidence to back this up but I think it’s plausible…

@piotr-oles I am having this issue with version “fork-ts-checker-webpack-plugin”: “7.2.1”. I have a monorepo with yarn workspaces > services using a shared library as a dependency, imports from the library fail with this TS6305:… error. It works fine when building locally with tsc -b.

For context on webpack config we’re using babel-loader as well as ts-loader (ts-loader has these options projectReferences: true, transpileOnly: true)