AGit instance produced by pickle deserialization always has aversion_info ofNone. This prevents version information from being accessed throughversion_info. It also causes theversion_info property not to satisfy its type annotation as a tuple ofints (independently of#1830). This is the case whether or notversion_info has been accessed on the original instance before it was pickled:

>>>importpickle,git>>>g=git.Git()>>>g.version_info(2,34,1)>>>g2=pickle.loads(pickle.dumps(g))>>>g2.version_info>>>

>>>importpickle,git>>>g=git.Git()>>>g2=pickle.loads(pickle.dumps(g))>>>g2.version_info>>>

This is due to an inconsistency in how the state of not yet having computedversion_info is represented in the backing attribute_version_info:

• Git usesLazyMixin caching for_version_info, which treats the attribute as uncomputed when absent and computed when present.
• Git defines__getstate__ and__setstate__ for pickling and unpickling to represent state pickling does not preserve by setting attributes toNone.

The_version_info attribute is set toNone on aGit object created by unpickling, so when accessing theversion_info property delegates to the_version_info attribute, its value ofNone is returned and theif attr == "_version_info" logic in the_set_cache_ method (inherited fromLazyMixin and overridden) is never run.

The intention is that an unpickledGit object haveversion_info in the uncomputed state. This works for the other two excluded attributes, which use the sameNone convention as in the__getstate__ and__setstate__ implementations, and which do not use anyLazyMixin functionality for their caching:

Unlike_version_info, which is managed by_set_cache_, thecat_file_all andcat_file_header attributes are initialized toNone inGit.__init__:

This is natural to fix at the same time as#1829, because a fix for that should change the way caching works.LazyMixin caching supports attributes that are computed once and never become stale, soversion_info/_version_info should implement caching in a different way to fix#1829, and that can fix this too if consistent with__getstate__/__setstate__.