It would be nice if we could have byte-for-byte "reproducible" builds; i.e.
if the input file and the lilypond versions are the same, they would produce
identical output.
Currently we can set pdfmodDate, but the PDF metadata "CreationData" field
is still set to the current time. It would be great if we could either omit
that field, or set it manually.
Test case: compile this twice (keeping the first pdf), then compare the
files. Ideally they would produce identical output.
\version "2.19.45"
\header {
% Works great!
pdfmodDate = "D:20150811160000+01'00'"
% Doesn't change anything; not currently supported.
pdfcreationDate = "D:20150811160000+01'00'"
}
{ c'4 }
I will note that both ModDate and CreationDate are optional in the PDF spec
(according to David):
https://lists.gnu.org/archive/html/lilypond-user/2016-07/msg00162.html
Cheers,
- Graham