Node ERR_PACKAGE_PATH_NOT_EXPORTED in CI - Fix the Exports Map Subpath

ERR_PACKAGE_PATH_NOT_EXPORTED means a package defines an exports map, and you imported a subpath the map does not expose, so the deep import is blocked.

What this error means

A node import throws Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: No "exports" main defined or Package subpath ... is not defined by exports, for a deep import into a dependency.

node

node:internal/modules/esm/resolve:282
Error [ERR_PACKAGE_PATH_NOT_EXPORTED]: Package subpath './lib/internal'
is not defined by "exports" in
/home/runner/work/app/app/node_modules/some-lib/package.json

Common causes

Importing a path the exports map does not list

The package restricts which files are importable via exports, and the deep path you used is not among them.

Relying on an internal file path that became private

A package added an exports map in a new version, locking down internals the code previously reached into.

How to fix it

Import a supported entry point

Check the package exports map for the public subpaths.
Import from a documented entry instead of the internal path.

JavaScript

import { thing } from 'some-lib';
// not: import { thing } from 'some-lib/lib/internal';

How to prevent it

Import only documented entry points, avoid reaching into a package internals, and review exports-map changes when upgrading dependencies.