> With data as (b"a" * _4G) the result is as expected: > > Traceback (most recent call last): > File "pickle-bigmem-test.py", line 5, in <module> > out = dumps(data) > OverflowError: cannot serialize a string larger than 4GB > > But with (b"a" * _2G), I get this: > > Traceback (most recent call last): > File "pickle-bigmem-test.py", line 7, in <module> > result = loads(out) > _pickle.UnpicklingError: BINUNICODE pickle has negative byte count Correction: these should be ("a" * _4G) and ("a" * _2G).