netcdf-perl-1.2.4-58.fc45 fails to build in Fedora 45:

+ cd netcdf-perl-1.2.4
+ cd src
+ make installed_manuals MANDIR=/builddir/build/BUILD/netcdf-perl-1.2.4-build/BUILDROOT/usr/share/man
make[1]: Entering directory '/builddir/build/BUILD/netcdf-perl-1.2.4-build/netcdf-perl-1.2.4/src'
mkdir -p /builddir/build/BUILD/netcdf-perl-1.2.4-build/BUILDROOT/usr/share/man/man1
chmod u+rwx,g+rws,o=rx /builddir/build/BUILD/netcdf-perl-1.2.4-build/BUILDROOT/usr/share/man/man1
case `uname -s` in \
    OSF1*|IRIX*|HP-UX) \
	sed \
     -e '/^\.TH/s/$D\ate: \([0-9]*\)\/\([0-9]*\)\/\([0-9]*\).*\$/\1-\2-\3/'\
	 netCDFPerl.1 > /builddir/build/BUILD/netcdf-perl-1.2.4-build/BUILDROOT/usr/share/man/man1/netCDFPerl.1;; \
    *) \
	sed \
     -e '/^\.TH/s/$D\ate: \([0-9]*\)\/\([0-9]*\)\/\([0-9]*\).*\$/\1-\2-\3/'\
	 netCDFPerl.1 | tbl | neqn > /builddir/build/BUILD/netcdf-perl-1.2.4-build/BUILDROOT/usr/share/man/man1/netCDFPerl.1;; \
esac
/usr/bin/neqn: line 59: exec: @g@eqn: not found

A difference between passing and failing build root is at <https://koschei.fedoraproject.org/build/22698783>. An upgrade of groff-base from 1.23.0-12.fc44 to 1.24.0-1.fc45 is suspicious.