Oh, I agree in principle, but as a user it means that something that worked up until poetry<1.2.0 broke. I understand that it's not their fault if Python distributions and packages don't comply with PEP440, and it's up to maintainers to fix it. Unfortunately, similar issues affect quite popular packages such as PyTorch, where the computation backend/version (cpu, cuda) is added as a local specifier ("1.12.1+cu116"), leading to all kinds of dependency resolver issues in poetry.

Edit: Notably, not in other tools such as pip.