This is where the stable ABI becomes critical: instead of building one wheel per Python, version packagers can build an “ abi3 ” wheel for the lowest supported Python version. However , none of the dials that control abi3-compatible wheel building talk to each other: it’s possibly to build an abi3-compatible wheel without tagging it as such, or to build a non-abi3 wheel and tag it incorrectly as compatible, or to tag an abi3-compatible wheel as compatible with the wrong CPython version. , none of the dials that control abi3-compatible wheel building talk to each other: it’s possibly to build an abi3-compatible wheel without tagging it as such, or to build a non-abi3 wheel and tag it incorrectly as compatible, or to tag an abi3-compatible wheel as compatible with the wrong CPython version.