BUG: ndarrays pickled by 1.16 cannot be loaded by 1.15.4 and lower #12869
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charris
added
00 - Bug
component: numpy._core
08 - Backport
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Backport of #12842.
Fixes #12837
When pickling ndarrays, the pickle protocol adds the reconstructing function's module
name to the pickled string so it can be called. The function (which is_reconstruct) now lives innumpy.core._multiarray_umath, but in pre-1.16 numpy it was innumpy.core.multiarray. Also for scalar objects, the functionscalar` moved.The fix is very simple, changing the
__module__attribute of_reconstructandscalarIn
array_reduce_ex, used when the pickle protocol is 5, the function will benumpy.core.numeric._frombuffer, which will not exist on pre-1.16 numpy (added in commit 64a855f, Oct 2018). I don't think we can work around that. People who do not have that function will have to modify their numpy if they wish to import protocol-5 pickled ndarrays.