Bug#792687: [Reproducible-builds] Bug#792687: gettext: please support timestamps from environment

[Daniel Shahaf]

Bruno Haible wrote on Sat, 15 Jul 2017 19:40 +0200:
> But SO WHAT? It does not get installed on the end user's system.

I am not disputing that .mo files, which are installed on user systems,
should be reproducible.

I am asserting that there is another workflow which would be simpler if
.po file headers were also reproducible.

> it's plain text, and it's a small diff.

This doesn't scale.  (For example, in my use-case, I'm dealing with a
5000-line unified diff full of one-line changes in date strings and C
comments and any number of other things. My goal is to get the number of
lines down to zero.)

So: should po file generation allow the caller to control the timestamp
that would be embedded?