C's function call mechanism requires internal maintenance of a call stack, which the programmer ordinarily never has to touch. The broken code author claims tha

C's function call mechanism requires internal maintenance of a call stack, which the programmer ordinarily never has to touch. The broken code author claims that he needs to manipulate said stack to write his Scheme interpreter. He does it wrong in a way that might pass the trivial "hello" test case under Linux, and blames Cygwin when it doesn't even pass that.