NSData.alloc().initWithBase64Encoding_ segfaults on OSX 10.15 beta (19A546d)

Created originally on Bitbucket by flindeberg (Fredrik Lindeberg)

Segfaults, both with .app and running the python script directly. Note Beta version of OSX.

Snippet from log:

Crashed Thread:        0  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x0000000000000038
Exception Note:        EXC_CORPSE_NOTIFY

Termination Signal:    Segmentation fault: 11
Termination Reason:    Namespace SIGNAL, Code 0xb
Terminating Process:   exc handler [8163]

Stack indicates it crashed quite directly on start (see attachments).