github/core package fails build because of exports map

The @github/core package has the following exports:

  "exports": {
    ".": {
      "types": "./lib/core.d.ts",
      "import": "./lib/core.js"
    }
  }

In a project which has type: "module", and simply import * as core from '@github/core', we get the following error:

ncc: Version 0.38.4 ncc: Compiling file index.js into ESM ncc: Using typescript@5.9.3 (local user-provided) Error: Module not found: Error: Package path . is not exported from package /code/node_modules/@actions/core (see exports field in /code/node_modules/@actions/core/package.json) Did you mean './@actions/core'?

im guessing this is because whatever throws this error is looking for a default export rather than import. or it is mistakenly looking up the non-existent CJS entrypoint.

im not sure what dependency of ncc throws this error so i haven't managed to debug it myself.