$ kstool systemz '.org .-x^0;x:'
Segmentation fault
$ valgrind kstool systemz '.org .-x^0;x:'
==17491== Stack overflow in thread 1: can't grow stack to 0xffe801ff8
==17491==
==17491== Process terminating with default action of signal 11 (SIGSEGV)
==17491== Access not within mapped region at address 0xFFE801FF8
==17491== at 0x50483E9: llvm::isa_impl<llvm::MCBinaryExpr, llvm::MCExpr, void>::doit(llvm::MCExpr const&) (Casting.h:56)