Dylan is a programming language originally developed by Apple, related to Smalltalk but hopefully more practical. The Gwydion Dylan suite contains MINDY, a bytecode compiler and interpreter, and d2c, a Dylan to C translator. Its build process is rather arcane, otherwise I would make an ebuild myself. Consider splitting the two major components into separate ebuilds. Reproducible: Always Steps to Reproduce:
I just added the Gwydion-Dylan ebuild to the tree. Please test it. A bit late from your report, but it is always better someday than never. ;-)