equivalents for devel/premake4, lang/ikarus, lang/stklos
and lang/ypsilon.
- Add mutual conflicts to lang/ikarus and lang/petite-chez
as they both install bin/scheme-script (reported by
Sulev-Madis Silber with his ports conflicts checker).
- Only define NO_PACKAGE for lang/ikarus when PACKAGE_BUILDING
is set (i.e. on the pointyhat cluster).
- Add regression-test target to lang/ypsilon.
PR: ports/168715
Submitted by: Vitaly Magerya <vmagerya@gmail.com> (maintainer)