Have to say though - Docker really makes this kind of thing a lot easier than it used to be. Trying this in the past used to be way harder - when the environment is contaminated with leftovers from previous failed attempts, it can be hard to determine if your process will actually work in a clean system.
Following up on my Python build woes last week, I finally got it sort of working.
In the end it was trying to use libraries that were in both `/usr/local/lib` (for `libpython`) and `/usr/local/lib64` (for `libssl` and `libcrypto`), but my existing configuration for the Python build was only looking in `/usr/local/lib`.
Next step is to figure out why Python isn't building/installing to `/usr/local/lib64`.