The lua checks in task's configure.ac are broken due to misuse of AC_ARG_WITH, and lua support is defined regardless of USE=lua. With USE=-lua and no previous lua install the build fails because of missing lua includes, see the attached build log. Thanks, James Reproducible: Always
Created attachment 249600 [details] app-misc:task-1.9.2:20101005-011833.log
On further inspection... The ncurses check is also broken due to misuse of AC_ARG_WITH, and is always disabled regardless of USE=ncurses.
Thanks for reporting. I've applied a patch which fixes the issue to a new ebuild revision and dropped the original ebuild. Note that the patch is more of a temporary fix while I push a better one upstream to fix the problem.