Hi all, As earlier Metapost user I have it installed and just saw the call for help while updating my system.
According to the discussion and supposed plan and SOURCE_DATE_EPOCH page I have a patch ready (see attachment), which follows the original coding style. A test looks ok: %%CreationDate: honors the environment variable, format is the same as before. Note: Patch was made against the Buster version (texlive-bin-2018.20181218.49446). I'm not a Debian developer/maintainer, so please check and adopt it according all your procedures (including QA). Kind regards, Gero
diff -ur texlive-bin.orig/texk/web2c/mplibdir/mp.w texlive-bin/texk/web2c/mplibdir/mp.w --- texlive-bin.orig/texk/web2c/mplibdir/mp.w 2019-08-03 22:48:47.000000000 +0200 +++ texlive-bin/texk/web2c/mplibdir/mp.w 2019-08-03 23:44:23.597334712 +0200 @@ -4350,7 +4350,11 @@ @c static void mp_fix_date_and_time (MP mp) { - time_t aclock = time ((time_t *) 0); + time_t aclock; + char *source_date_epoch; + if ((source_date_epoch = getenv("SOURCE_DATE_EPOCH")) == NULL || + (aclock = (time_t) strtoll(source_date_epoch, NULL, 10)) <= 0) + aclock = time ((time_t *) 0); struct tm *tmptr = localtime (&aclock); set_internal_from_number (mp_time, unity_t); number_multiply_int (internal_value(mp_time), (tmptr->tm_hour * 60 + tmptr->tm_min));