% ./testassert 
error: invalid integer math: integerAddWithOverflow(127ss, 1ss)
backtrace:
0   testassert                          0x000000010bf83378 clay_showBacktrace() + 88
1   testassert                          0x000000010bf91e10 clay_errorNoThrow(StringConstant, Static[integerAddWithOverflow], StringConstant, ReprFormatter[Tuple[CapturedLValue[Int8], CapturedLValue[Int8]]], StringConstant) + 928
2   testassert                          0x000000010bf7c541 clay_c(Int8) + 1601
3   testassert                          0x000000010bf7bec5 clay_b() + 21
4   testassert                          0x000000010bf7be7d clay_a() + 13
5   testassert                          0x000000010bf7be3d clay_main() + 13
6   testassert                          0x000000010bf7bbe7 clay_callMain(Static[main]) + 23
7   testassert                          0x000000010bf7bb07 main + 103
8   testassert                          0x000000010bf7b7b4 start + 52
zsh: abort      ./testassert