It has been observed that crash handler can now corrupt memory during __cxa_demangle (from libc++). Repro steps listed here are just one of possible ways to trigger it, very similar crashes have been observed in the wild with servers (see attached logs).
More info: _cxa_demangle() called on this symbol: _ZNK10TTupleImplI16TIntegerSequenceIjJEEJEE10ApplyAfterI21TMemberFunctionCallerI16SConsoleInputBoxMS5_FvRK5FTextN11ETextCommit4TypeEEEJS8_RSA_EEEDTclfp_spcl7ForwardIT0_Efp0_EEEOT_DpOSF seemed to corrupt the memory around GLog. Assumption that it runs out of crash handling stack turned out to be incorrect :/
1. Build DebugSet (make DebugSet)
2. Run UE4Editor-Linux-Debug and create a blueprint project
3. Type "debug crash" and watch closely the editor console
4. Observe that crash will happen before the callstack is printed and CRC will not be run
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-34450 in the post.