GNU Solfege 3.22.2 refuses to build. Here is what I believe is the relevant part of the log file:
Converting to PNG...LC_ALL=C makeinfo -I topdocs --no-split --no-headers --output FAQ topdocs/FAQ.texi utf8 "\xF6" does not map to Unicode at /gnu/store/w8k9hcigvhzrlrblv8lgqj77sm3833rs-texinfo-6.7/share/texinfo/Texinfo/ParserNonXS.pm line 1796, <FH> line 169. Malformed UTF-8 character: \xf6\x20\x41\x63 (unexpected non-continuation byte 0x20, immediately after start byte 0xf6; need 4 bytes, got 1) in pattern match (m//) at /gnu/store/w8k9hcigvhzrlrblv8lgqj77sm3833rs-texinfo-6.7/share/texinfo/Texinfo/ParserNonXS.pm line 3364. Malformed UTF-8 character (fatal) at /gnu/store/w8k9hcigvhzrlrblv8lgqj77sm3833rs-texinfo-6.7/share/texinfo/Texinfo/ParserNonXS.pm line 3364. make[1]: *** [Makefile:83: README] Error 25 make[1]: *** Waiting for unfinished jobs.... Deleting `inverting-intervals.eps'... Layout output to `inverting-intervals-1.eps'... Writing inverting-intervals-systems.texi... Writing inverting-intervals-systems.tex... Writing inverting-intervals-systems.count... Success: compilation successfully completed make[1]: Leaving directory '/tmp/guix-build-solfege-3.22.2.drv-0/solfege-3.22.2' make: *** [Makefile:74: genfiles] Error 2 command "make" "-j" "4" failed with status 2