Hi. The support of SOURCE_DATE_EPOCH added in pdftex/dvipdfm-x is great, and does a very good job at building reproducible binary software packages. SOURCE_DATE_EPOCH allows to fix the metadata timestamps in the compiled document, and when SOURCE_DATE_EPOCH_TEX_PRIMITIVES is set to 1, the tex primitives \year, \month etc. are also fixed, so that for example \today refers to the date given by SOURCE_DATE_EPOCH.
The SOURCE_DATE_EPOCH environment variable is always used to get reproducible builds, and in this context, SOURCE_DATE_EPOCH_TEX_PRIMITIVES is always set to 1. This is fine when working with tex documents only. However in a more general context, for example debian reproducible build effort  (which has equivalents for other distributions ), the need to set another tool-specific environment variable has been criticized: adding such tool-specifc envvar handling in general package-building tools is considered to be endless and so discarded. Therefore, I would like to support a solution where the default value of SOURCE_DATE_EPOCH_TEX_PRIMITIVES is set to to 1. It has already been mentioned by Norman Gray . The only drawback is that we brake backward-compatibility in a situation where someone already uses SOURCE_DATE_EPOCH for another task, and don't set SOURCE_DATE_EPOCH_TEX_PRIMITIVES. In this situation, the default value 0 of SOURCE_DATE_EPOCH_TEX_PRIMITIVES allows this user to get the same content in the compiled document. I do think this situation is very unlikely. Another solution is to drop SOURCE_DATE_EPOCH_TEX_PRIMITIVES as if it is always set to 1, but I understand that it has to be kept if someone thinks it can be useful. Whatever will be your answer, I thank you again for your welcome regarding reproducibility questions. Regards, Alexis Bienvenüe.  https://wiki.debian.org/ReproducibleBuilds/  https://reproducible-builds.org/  https://www.tug.org/pipermail/tex-k/2016-May/002703.html _______________________________________________ Reproducible-builds mailing list Reproduciblefirstname.lastname@example.org http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/reproducible-builds