Re: Set FORCE_SOURCE_DATE=1 by default

["Ludovic Courtès" <ludo@gnu.org>]

Hi!

Vagrant Cascadian <vagrant@reproducible-builds.org> skribis:

> From 7a39330b56934accef14b5e2ac003e211c7c6c5b Mon Sep 17 00:00:00 2001
> From: Vagrant Cascadian <vagrant@reproducible-builds.org>
> Date: Fri, 10 Jun 2022 16:12:59 -0700
> Subject: [PATCH] guix: gnu-build-system: Set FORCE_SOURCE_DATE in
>  set-SOURCE-DATE-EPOCH phase.
>
> * guix/build/gnu-build-system.scm (set-SOURCE-DATE-EPOCH): Set
>   FORCE_SOURCE_DATE=1. Update URL.

[...]

>  (define* (set-SOURCE-DATE-EPOCH #:rest _)
> -  "Set the 'SOURCE_DATE_EPOCH' environment variable.  This is used by tools
> -that incorporate timestamps as a way to tell them to use a fixed timestamp.
> -See https://reproducible-builds.org/specs/source-date-epoch/."
> -  (setenv "SOURCE_DATE_EPOCH" "1"))
> +  "Set the 'SOURCE_DATE_EPOCH' and 'FORCE_SOURCE_DATE' environment variables.
> +This is used by tools that incorporate timestamps as a way to tell them to use
> +a fixed timestamp.  See https://reproducible-builds.org/docs/source-date-epoch/."
> +  (setenv "SOURCE_DATE_EPOCH" "1")
> +  (setenv "FORCE_SOURCE_DATE" "1"))

I’d mention above that FORCE_SOURCE_DATE is honored exclusively by
TeX Live.

It’s a bit of a bummer that we have to do that here, but as you point
out, TeX Live can be used pretty much in any package and we’d rather not
track every possible issue by hand.

I think it can go to ‘core-updates’.

Thanks!

Ludo’.