po4a version 0.70 and newer appear to have changed the API enough that the IkiWiki po plugin is broken.

This was reported as a FTBFS bug in Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1072760

I think this patch is sufficient: https://salsa.debian.org/jmtd/ikiwiki/-/commit/65f13f08901806a3b458cd625369e27bf19722e0

— Jon, 2024-06-11

I've pushed a Debian package update with a slightly more involved patch:

https://salsa.debian.org/debian/ikiwiki/-/blob/debian/master/debian/patches/0001-Adjustments-for-po4a-0.7.0.patch?ref_type=heads

I'm unavailable for a couple of weeks so I'll let it "soak" in Debian before committing it here. — Jon, 2024-06-12