The following code looks correct:

```python
import os

class A(os.PathLike):
    pass

class B(os.PathLike):
    pass

assert issubclass(A, os.PathLike) # direct inheritance relationship
assert issubclass(B, os.PathLike) # direct inheritance relationship
assert not issubclass(A, B) # A is not derived from B or vice-versa
```

On Python 3.7.0-3.7.6 and 3.8.0-3.8.1 the third assertion fails. The expected behavior was restored in 3.7.7 and 3.8.2. This seems to be around when the internals of `abc` were translated to C.

Given that the behavior was fixed, but a bug fix matching this behavior wasn't listed in the changelog, the only resolution is to document that this behavior may be extant in older but still supported minor versions of Python. Where should that text be placed?

Since those releases are no longer supported, I don't think there's any place you could put this that would be seen. And we wouldn't want to put a note in a current release about a bug in a non-supported version that was fixed in another non-supported version.

Understood. It's probably good practice to keep the interpreter version up to date in any case when debugging.