https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71851
--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Daniel Gutson from comment #5) > This macro would change break reproduceability as much as __TIME__ does. __TIME__ is now being warned on if requested (-Wdate-time), and can be changed through environment variables - SOURCE_DATE_EPOCH env var - and for -fcompare-debug SOURCE_DATE_EPOCH is set by the driver for both invocations the same. So, as you can see, there is a strong shift away from __DATE__/__TIME__.