(lldb) up
frame #21: 0x000000010012468c openttd`RoadVehicle::GetMaxTrackSpeed() const + 284
openttd`RoadVehicle::GetMaxTrackSpeed:
->  0x10012468c <+284>: leaq   0x308d3b(%rip), %rdi      ; "Assertion failed at line %i of %s: %s"
    0x100124693 <+291>: leaq   0x310a31(%rip), %rdx      ; "/Users/andy2/workspace/OpenTTD.andythenorth/src/road_map.h"
    0x10012469a <+298>: leaq   0x310a65(%rip), %rcx      ; "MayHaveRoad(t)"
    0x1001246a1 <+305>: movl   $0xa6, %esi