How/where are you referencing mmap64? Could some include be missing or path issue?
ref/gcc-12.3.0/libphobos/libdruntime/core/internal/gc/os.d:145 ref/gcc-12.3.0/libphobos/libdruntime/core/thread/fiber.d:1050 host/lib/gcc/i686-linux-musl/12.3.0/../../../../i686-linux-musl/lib/libgphobos.a(os.o) etc
