This package currently fails to build with the following error:

--8<---------------cut here---------------start------------->8---
ui/gtk/gens/gens_window_callbacks.cpp:157:15: error: ‘GdkDragContext {aka struct _GdkDragContext}’ has no member named ‘targets’
  if (context->targets)
               ^~~~~~~
--8<---------------cut here---------------end--------------->8---

Nix has nothing special in its definition: https://github.com/NixOS/nixpkgs/tree/master/pkgs/misc/emulators.

-- 
Pierre Neidhardt
https://ambrevar.xyz/