Attaching a debdiff that partially addresses this problem.
Unfortunately this is not enough as it seems that we're hitting another issue with po4a, for which I've submitted a patch upstream: https://github.com/mquinson/po4a/pull/515
With both fixes i can build pppconfig again.
diff -Nru pppconfig-2.3.28/debian/changelog pppconfig-2.3.29/debian/changelog --- pppconfig-2.3.28/debian/changelog 2023-12-09 14:54:57.000000000 +0100 +++ pppconfig-2.3.29/debian/changelog 2024-08-20 15:20:42.000000000 +0200 @@ -1,3 +1,10 @@ +pppconfig (2.3.29) UNRELEASED; urgency=medium + + * Specify that the french addendum has encoding iso-8859-1. + Fixes build with new po4a (Closes: #1072606). + + -- Alessandro Astone <alessandro.ast...@canonical.com> Tue, 20 Aug 2024 15:20:42 +0200 + pppconfig (2.3.28) unstable; urgency=medium * QA upload. diff -Nru pppconfig-2.3.28/man/po/pppconfig.pot pppconfig-2.3.29/man/po/pppconfig.pot --- pppconfig-2.3.28/man/po/pppconfig.pot 2015-08-28 12:00:00.000000000 +0200 +++ pppconfig-2.3.29/man/po/pppconfig.pot 2024-08-20 15:20:42.000000000 +0200 @@ -7,13 +7,13 @@ msgid "" msgstr "" "Project-Id-Version: PACKAGE VERSION\n" -"POT-Creation-Date: 2011-06-07 20:27+0300\n" +"POT-Creation-Date: 2024-08-20 15:22+0200\n" "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" "Language-Team: LANGUAGE <l...@li.org>\n" "Language: \n" "MIME-Version: 1.0\n" -"Content-Type: text/plain; charset=CHARSET\n" +"Content-Type: text/plain; charset=UTF-8\n" "Content-Transfer-Encoding: 8bit\n" #. type: TH diff -Nru pppconfig-2.3.28/man/po4a.cfg pppconfig-2.3.29/man/po4a.cfg --- pppconfig-2.3.28/man/po4a.cfg 2015-08-28 12:00:00.000000000 +0200 +++ pppconfig-2.3.29/man/po4a.cfg 2024-08-20 15:20:42.000000000 +0200 @@ -1,2 +1,3 @@ [po4a_paths] man/po/pppconfig.pot fr:man/po/fr.po de:man/po/de.po pt:man/po/pt.po -[type: man] man/pppconfig.8 fr:man/pppconfig.fr.8 add_fr:man/pppconfig.add.fr de:man/pppconfig.de.8 add_de:man/pppconfig.add.de pt:man/pppconfig.pt.8 +[type: man] man/pppconfig.8 fr:man/pppconfig.fr.8 add_fr:man/pppconfig.add.fr de:man/pppconfig.de.8 add_de:man/pppconfig.add.de pt:man/pppconfig.pt.8 \ + opt_fr:"--addendum-charset iso-8859-1"