I'm getting a build error when compiling libksba git master commit ce1de8cb2bcd712381f77519de4da87af42879a4 under Gentoo Linux using GCC 12.0.0-commit-34fac9ef724ab7c1bee69aaa214327e2cb8bef30-20210920. Here is a snippet of the error with the full log attached.

l{F2648775}

libtool: link: x86_64-pc-linux-gnu-ar cr .libs/libgnu.a .libs/dummyobj.o
libtool: link: x86_64-pc-linux-gnu-ranlib .libs/libgnu.a
libtool: link: ( cd ".libs" && rm -f "libgnu.la" && ln -s "../libgnu.la" "libgnu.la" )
make[3]: Leaving directory '/var/tmp/portage/dev-libs/libksba-9999/work/libksba-9999/gl'
make[2]: Leaving directory '/var/tmp/portage/dev-libs/libksba-9999/work/libksba-9999/gl'
Making all in src
make[2]: Entering directory '/var/tmp/portage/dev-libs/libksba-9999/work/libksba-9999/src'
test -f asn1-parse.c || /bin/sh ../build-aux/ylwrap asn1-parse.y y.tab.c asn1-parse.c y.tab.h echo asn1-parse.c | sed -e s/cc$/hh/ -e s/cpp$/hpp/ -e s/cxx$/hxx/ -e s/c++$/h++/ -e s/c$/h/ y.output asn1-parse.output -- bison -o y.tab.c
x86_64-pc-linux-gnu-gcc \

 -I. -DBUILD_GENTOOLS -o asn1-gentables \
./asn1-gentables.c \
        `test -f 'asn1-parse.c' || echo './'`asn1-parse.c  \
        ./asn1-func.c      \
        ./gen-help.c

asn1-parse.y: In function 'yylex':
asn1-parse.y:861:20: error: 'yytoknum' undeclared (first use in this function)

861 |             return yytoknum[k];                                                                                                                                                        
    |                    ^~~~~~~~

asn1-parse.y:861:20: note: each undeclared identifier is reported only once for each function it appears in
make[2]: * [Makefile:1245: asn1-gentables] Error 1
make[2]: Leaving directory '/var/tmp/portage/dev-libs/libksba-9999/work/libksba-9999/src'
make[1]: * [Makefile:486: all-recursive] Error 1
make[1]: Leaving directory '/var/tmp/portage/dev-libs/libksba-9999/work/libksba-9999'
make: *** [Makefile:418: all] Error 2