The date is embedded in a shipped PDF file:

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/diffoscope-results/clhep.html

  ./usr/share/doc/clhep/GenericFunctions/genericFunctions.pdf.gz

  November·24,·2025
  vs.
  December·27,·2026

The attached patch sets FORCE_SOURCE_DATE in debian/rules to ensure that
texlive respects SOURCE_DATE_EPOCH for a reproducible date.

According to my local tests, with this patch applied clhep should
build reproducibly on tests.reproducible-builds.org!

Thanks for maintaining clhep!

live well,
  vagrant

I can confirm that this is still an issue, and the patch still fixes it.

I would like to perform a Non-Maintainer Upload (NMU) in the coming
weeks applying the patch. Please let me know if there are outstanding
concerns!

live well,
  vagrant

I have uploaded an NMU to DELAYED/10, debdiff attached, and also
proposed a merge request:

https://salsa.debian.org/science-team/clhep/-/merge_requests/1

live well,
  vagrant

We believe that the bug you reported is fixed in the latest version of
clhep, which is due to be installed in the Debian FTP archive.

A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 1121406@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Santiago Vila <sanvila@debian.org> (supplier of updated clhep package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@ftp-master.debian.org)
Format: 1.8
Date: Sun, 18 Oct 2026 00:55:00 +0200
Source: clhep
Architecture: source
Version: 2.4.7.1-3
Distribution: unstable
Urgency: medium
Maintainer: Debian Science Maintainers <debian-science-maintainers@lists.alioth.debian.org>
Changed-By: Santiago Vila <sanvila@debian.org>
Closes: 1121406
Changes:
 clhep (2.4.7.1-3) unstable; urgency=medium
 .
   * Team upload.
 .
   [ Vagrant Cascadian ]
   * debian/rules: Set FORCE_SOURCE_DATE=1 for reproducible PDF generation.
     Closes: #1121406.
 .
   [ Santiago Vila ]
   * Update some lintian overrides.
   * Drop "Rules-Requires-Root: no" (default).
   * Drop "Priority: optional" (default).
   * Update standards-version.
Checksums-Sha1:
 464450b1afe6911a972eb9d275ec0b3667dfeaa4 1800 clhep_2.4.7.1-3.dsc
 dd0d37a7527b456c0b2fef059512515ec2116aaf 6056 clhep_2.4.7.1-3.debian.tar.xz
 e2ff82f2f585acfc32c18b67dd59c686dcb5e399 8021 clhep_2.4.7.1-3_source.buildinfo
Checksums-Sha256:
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 297b5aedc8bec8d0d9bf6d5988daa7abde6244198353946306f5fae4d382173e 6056 clhep_2.4.7.1-3.debian.tar.xz
 bec9d0e288f0823a9b7f37fab3ee950681ff4b2a71efe3d045728f70a90c50d8 8021 clhep_2.4.7.1-3_source.buildinfo
Files:
 650db08086472832c2e2de6a31d96ee4 1800 science optional clhep_2.4.7.1-3.dsc
 5944b0bed8dccf32d580cb3eb82c22d8 6056 science optional clhep_2.4.7.1-3.debian.tar.xz
 452339dd323e644a2be6d4d7724e3cbf 8021 science optional clhep_2.4.7.1-3_source.buildinfo
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