utypes.c:16: Include file <sys/types.h> matches the name of a POSIX library,
    but the POSIX library is not being used.  Consider using +posixlib or
    +posixstrictlib to select the POSIX library, or -warnposix to suppress this
    message.
utypes.c: (in function f)
utypes.c:26:8: Variable src_bytes declared but not used

Finished checking --- 2 code warnings, as expected