gcc/testsuite/g++.dg/modules/cpp-20.C

// { dg-do preprocess }
// { dg-additional-options "-fmodules-ts" }

#define baz(x)
#define qux(x)
export module foo.bar baz(:) : garply qux(.);	// { dg-error "':' in module name or partition comes from or after macro expansion" }

int i;