Dumping my personal notes here as backup and in case anyone else wants to know how this is going.


1. `__package__`
    - [x]  Make sure all uses of the attribute fall back on `__spec__` (done way back when)
    - [x]  Add an `ImportWarning` when the attribute is used but it differs from `__spec__`  (3.6)
    - [x]  Update code to prefer the spec over the attribute, raising `ImportWarning` when having to fall back to the attribute (3.10)
    - [ ]  Change `ImportWarning` to `DeprecationWarning` when falling back to the attribute
    - [ ]  Remove code in `importlib` that used the old attribute
2. `__loader__`
    - [x]  Make sure all Python code uses of the attribute fall back on `__spec__` (3.10)
    - [ ]  Update C code to fall back to using `__spec__` ([issue](https://bugs.python.org/issue42132))
    - [ ]  Add an `ImportWarning` when the attribute is used but it differs from `__spec__`
    - [ ]  Update code to prefer the spec over the attribute, raising `ImportWarning` when having to fall back to the attribute
    - [ ]  Change `ImportWarning` to `DeprecationWarning` when falling back to the attribute
    - [ ]  Remove code in `importlib` that used the old attribute
3. `__cached__`
    - [ ]  Make sure all uses of the attribute fall back on `__spec__`
    - [ ]  Add an `ImportWarning` when the attribute is used but it differs from `__spec__`
    - [ ]  Update code to prefer the spec over the attribute, raising `ImportWarning` when having to fall back to the attribute
    - [ ]  Change `ImportWarning` to `DeprecationWarning` when falling back to the attribute
    - [ ]  Remove code in `importlib` that used the old attribute