According to Repology, the current upstream release is 2.0.0. Please bump.
Created attachment 611514 [details] Ebuild and patch for nudoku-2.0.0 This is an ebuild for nudoku-2.0.0, as well as a patch for https://bugs.gentoo.org/677702. https://bugs.gentoo.org/677702 is caused by the ncurses library being split into ncurses and tinfo, so the patch detects that using PKG_CHECK_MODULES in configure.ac and adds the appropriate linker flags in src/Makefile.am. It also rebuilds the CAIRO conditional to conform to https://www.gnu.org/software/automake/manual/html_node/Usage-of-Conditionals.html, although we don't currently have a USE flag to enable Cairo support.
Sorry I don't have any Gentoo machines running anymore. I'll try to install one ASAP and take care of the bugs assigned to me.