Since all references is now checked prepass, dead code can cause errors. For example, a function that never gets called will now generate an error:
.function myFunc1() { .var x = unknownSymbol; // Error: Undefined symbol }
If-directives inside functions/defines is now scoped, meaning you can't do like this anymore (This is already the case for .if directives outside functions/defines):
.function myFunc1(flag) { .if (flag) .var message = "flag is true" else .var message = "flag is false" .print message // Error - 'message' is unknown }