[pdftex] ID string in final PDF vs. same PDF checksum for sameinputs

[Akira Kakuto]

> I am currently trying to create PDFs with
> the same checksum for the same inputs.

If you are using TeX Live 2016, try to set environment
variables like
SOURCE_DATE_EPOCH=1486439625
SOURCE_DATE_EPOCH_TEX_PRIMITIVES=1

The latter will be changed in TeX Live 2017 as
FORCE_SOURCE_DATE=1

Best,
Akira