@ConorO'Brien This was the issue. The second one works now.

@Dennis awesome! thank you!

There might be more bugs. If I compile Foo with -O2, it prints two error messages (Stack is empty. and Unknown mode for '$') for the Hello World program.

@Pavel tio.run/#tapebagel

hm.... could be more UB accessing invalid memory? there aren't any $s in the HW program

@ConorO'Brien Yep.

aha! nice find!

@Dennis Could you pull Attache, please?