This backward incompatibility was unintentionally introduced in importlib_metadata 3.6 (https://importlib-metadata.readthedocs.io/en/latest/history.html#v3-6-0, released Feb 23) and was previously reported in https://github.com/python/importlib_metadata/issues/300. While technically it's a breaking change, here's my analysis from that issue:

> Basically what it boils down to is that access by index of a `Distribution.entry_points` was dropped, but that appears not to be a problem. At least, this is the first report of such a problem. The assumption has been, and the tests bear this out implicitly, that the consumer of `Distribution.entry_points` will be iterated over and not accessed by index.

My assessment is that the issue is theoretically incompatible but in practice, this usage is not found in the wild. If there was a substantial need to maintain compatibility for this use-case, I'd definitely consider adding such compatibility. As it stands, however, I'm unaware of even a single use case that demands this interface.

Given the non-issue this has been for importlib_metadata, I expect it to be a non-issue for Python 3.10 as well.