On 2022-06-23, Maxim Cournoyer wrote:
>>> Perhaps to show our stand here we could patch our copy of pdftex with
>>> 's/FORCE_SOURCE_DATE/SOURCE_DATE_EPOCH/', lest we end up with a grocery
>>> list of *SOURCE_DATE* variable variants.
>>
>> Sure, with some technical details fixed up, as I think they are
>> functionally different, in that FORCE_SOURCE_DATE is a boolean, and
>> SOURCE_DATE_EPOCH is an integer, though ... Guix sets
>> SOURCE_DATE_EPOCH=1 ... so it might just work by dumb luck! Though There
>> may be some rare packages that need SOURCE_DATE_EPOCH to be some larger
>> value...  "It can't possibly be 1970, this program was first written in
>> 2002, there must be some error, failing build..."
>>
>> At any rate, if diverging from upstream Tex Live is how Guix wants to
>> handle this, I'm all for it!
>
> Seems we have a small consensus here (Ludo, you and myself); would you
> like to give it a try?

My first naive attempt appeared to build, but failed lots of test
suites... so that clearly needs some more work!

diff --git a/gnu/packages/tex.scm b/gnu/packages/tex.scm
index f6b4c25595..e8c99d202b 100644
--- a/gnu/packages/tex.scm
+++ b/gnu/packages/tex.scm
@@ -395,6 +395,12 @@ (define-public texlive-bin
                      (("srcdir/tests/pprecA-0.ind pprecA-0.ind1 \\|\\| exit 1")
                       "srcdir/tests/pprecA-0.ind pprecA-0.ind1 || exit 77")))))
              '())
+         (add-after 'unpack 'default-to-force-source-date
+           ;; https://lists.gnu.org/archive/html/guix-devel/2022-06/msg00330.html
+           (lambda _
+             ;; texk/web2c/lib/texmfmp.c:  string sde_texprim = getenv ("FORCE_SOURCE_DATE");
+             (substitute* "texk/web2c/lib/texmfmp.c"
+                (("getenv ..FORCE_SOURCE_DATE..") "1"))))
          (add-after 'unpack 'unpack-texlive-extra
            (lambda* (#:key inputs #:allow-other-keys)
              (mkdir "texlive-extra")


No idea if this approach would have any side-effects ... there is some
code that checks if both FORCE_SOURCE_DATE and SOURCE_DATE_EPOCH are set
... but i *think* this is the only spot where it directly checks if
FORCE_SOURCE_DATE is set. It would also be good to support
FORCE_SOURCE_DATE=0 if there is in fact some real-world use-case with
SOURCE_DATE_EPOCH is set and FORCE_SOURCE_DATE should be "0".

I'll try with tests disabled to see if it at least fixes the issue in
the two packages (itpp, discrover) that manually set FORCE_SOURCE_DATE.


live well,
  vagrant