# The error `env.shadow`

**environment**: something the run needs is missing or different where it runs (a package, a file, a device, the network): the error names what to install, fetch or attach.

Where MIME gives it, with what its message says happened and what its action says to do (`{…}` is filled in from the experiment):

- in `mime/env/_check.py`:
  - what happened: `Python imports {…} from {…}, not from this environment's site-packages ({…})`
  - what to do: `unset PYTHONPATH and remove the path from sys.path (PYTHONNOUSERSITE=1 for the user site), so that the pinned copy is the one imported`

Reading an error and reaching its full traceback: [reading an error](../reading_errors.md). Every code: [the index](index.md).