Python forward compatibility & numpy
At the time of writing the most recent version of Python is 3.14.2. If you use this version then this innocuous looking sequence of commands will result in a seriously broken environment:
Requires-Python upper limits Requires-Python was added to allow older versions of Python to be dropped by packages without breaking installation on older versions of Python. Currently (and for the last 4+ years), pip handles this quite simply; Requires-Python is a free-form SpecifierSet, and it checks to see if the current version of Python is included in the set. If not, it starts going back through a package’s history to find the most recent passing version. This was prompted by IPython droppi...
At the time of writing the most recent version of Python is 3.14.2. If you use this version then this innocuous looking sequence of commands will result in a seriously broken environment: