MechanicalSoup itself is fine; its import chain runs `from bs4 import BeautifulSoup`, and the `bs4` on this system is the dummy `bs4` 0.0.1 stub from PyPI (installed by `pip install bs4`), which contains no code. Run `pip uninstall bs4 -y` then `pip install beautifulsoup4`, and `import mechanicalsoup` works. On modern Python the same trap prints the newer quoted message.

## The error

```text
ImportError: cannot import name BeautifulSoup
```

## Fix it

1. **Check for the stub package**

```
python -m pip show bs4
```
Expected: if it reports version 0.0.1, that is the placeholder package. A real beautifulsoup4 shows as `beautifulsoup4` with version 4.x.

2. **Remove the stub, install the real library**

```
python -m pip uninstall bs4 -y
python -m pip install beautifulsoup4
```
Expected: the stub is gone and beautifulsoup4 4.x is installed.

3. **Confirm the whole chain**

```
python -c "import mechanicalsoup; print('ok')"
```
Expected: prints `ok`. The `from bs4 import BeautifulSoup` inside mechanicalsoup now finds the real class.

## When this applies

- `import mechanicalsoup` fails with `ImportError: cannot import name BeautifulSoup` (old-style, no quotes)
- the traceback shows mechanicalsoup's `__init__` -> `browser.py` -> `form.py` -> `from bs4 import BeautifulSoup`
- `pip show bs4` reports version 0.0.1

## When it does NOT apply

- `ModuleNotFoundError: No module named 'bs4'` means nothing named bs4 exists at all
- the quoted modern form (`cannot import name 'BeautifulSoup' from 'bs4'`) is the same trap on newer Python
- `No module named 'mechanicalsoup'` means MechanicalSoup itself is missing

## Compatibility

Seen on Python 2 / early Python 3, which printed the unquoted message format. The underlying stub-package trap exists on every Python version.

## Variant phrasings

### `ImportError: cannot import name 'BeautifulSoup' from 'bs4'`

The same stub-package trap as printed by Python 3.6+. Same fix: uninstall the `bs4` stub, install `beautifulsoup4`.

## Why it happens

PyPI hosts a placeholder package literally named `bs4` (version 0.0.1) whose only content is a note saying to install beautifulsoup4 instead. `pip install bs4` installs that empty shell. MechanicalSoup imports `from bs4 import BeautifulSoup` during its own import, so the empty shell breaks `import mechanicalsoup` even though MechanicalSoup itself is correctly installed. Old Pythons printed the message without quotes or the from-clause, which is the exact string here.

## Edge cases

- Kodi-style addon environments vendor old library copies. If uninstalling the stub is not possible there, make sure beautifulsoup4 is installed in the same addon lib folder and takes precedence.
- After removing the stub, clear `__pycache__` in the project. A cached empty bs4 module can linger.