This isn't a general problem, but I have been seriously burnt by a change from a minor version upgrade.
In 3.8 someone decided that they didn't like the way people were excepting the Exception for cancelled asycnio tasks. So they changed the cancelled task exception to inherit from base exception instead of exception. This meant a bunch of well used libraries immediately had a load of subtle bugs that in normal operation just didn't happen. I can't remember the exact details but I think when the bug did happen the task queue would just continue to grow until we ran out of memory.
This change wasn't a bug fix, more an optimization or an attempt to get people to code a certain way.
I'm all in favour of bug fixes, but Devs shouldn't have to worry about minor upgrades breaking everything.
In 3.8 someone decided that they didn't like the way people were excepting the Exception for cancelled asycnio tasks. So they changed the cancelled task exception to inherit from base exception instead of exception. This meant a bunch of well used libraries immediately had a load of subtle bugs that in normal operation just didn't happen. I can't remember the exact details but I think when the bug did happen the task queue would just continue to grow until we ran out of memory.
This change wasn't a bug fix, more an optimization or an attempt to get people to code a certain way.
I'm all in favour of bug fixes, but Devs shouldn't have to worry about minor upgrades breaking everything.
See https://bugs.python.org/issue32528