>>> Emerging : portage://games-emulation/gens-2.15.5-r2:run?{[]}

These are the packages that would be merged, in order:

Calculating dependencies... done!

 └─step  1─┤ unmask  portage://games-emulation/gens-2.15.5-r2

 └─step  2─┤ verify  media-libs/libsdl (unsatisfied constraints, assumed installed)
             │ verify  media-libs/libsdl (unsatisfied constraints, assumed running)
             │ verify  x11-libs/gtk+ (unsatisfied constraints, assumed installed)
             │ verify  x11-libs/gtk+ (unsatisfied constraints, assumed running)
             │ download  portage://games-emulation/gens-2.15.5-r2
             │           └─ file ─┤ 724.46 Kb  	 gens-2.15.5.tar.gz

 └─step  3─┤ install   portage://games-emulation/gens-2.15.5-r2 (unmasked)

 └─step  4─┤ run     portage://games-emulation/gens-2.15.5-r2

Total: 4 actions (1 unmask, 1 download, 1 install, 1 run), grouped into 4 steps.
       724.46 Kb to be downloaded.



>>> Assumptions taken during proving & planning:

  Package unmask (1 package):
  Add to /etc/portage/package.unmask:
    =games-emulation/gens-2.15.5-r2


Error The proof for your build plan contains domain assumptions. Please verify:


>>> Domain assumptions

- REQUIRED_USE violation: 
  media-libs/libsdl
  No ebuild satisfies USE deps for portage://media-libs/libsdl-1.2.78 (use_dep_unsat)
  USE deps force:   [abi_x86_32,joystick,video]
  conflicts with profile use.mask / use.force
  required by: portage://games-emulation/gens-2.15.5-r2

- REQUIRED_USE violation: 
  media-libs/libsdl
  No ebuild satisfies USE deps for portage://media-libs/libsdl-1.2.78 (use_dep_unsat)
  USE deps force:   [abi_x86_32,joystick,video]
  conflicts with profile use.mask / use.force
  required by: portage://games-emulation/gens-2.15.5-r2

- REQUIRED_USE violation: 
  x11-libs/gtk+
  No ebuild satisfies USE deps for portage://x11-libs/gtk+-2.24.33-r4 (use_dep_unsat)
  USE deps force:   [abi_x86_32]
  conflicts with profile use.mask / use.force
  required by: portage://games-emulation/gens-2.15.5-r2

- REQUIRED_USE violation: 
  x11-libs/gtk+
  No ebuild satisfies USE deps for portage://x11-libs/gtk+-2.24.33-r4 (use_dep_unsat)
  USE deps force:   [abi_x86_32]
  conflicts with profile use.mask / use.force
  required by: portage://games-emulation/gens-2.15.5-r2


>>> Bug report drafts (Gentoo Bugzilla)

---
Summary: portage://games-emulation/gens-2.15.5-r2: unsatisfied_constraints dependency on media-libs/libsdl

Affected package: portage://games-emulation/gens-2.15.5-r2
Dependency: media-libs/libsdl
Phases: [install,run]

Unsatisfiable constraint(s):
  media-libs/libsdl-

Observed:
  portage-ng reports no available candidate satisfies the above constraint(s).
  Available versions in repo set (sample, first 2 of 2): [1.2.68,1.2.78]

Potential fix (suggestion):
  Review dependency metadata in portage://games-emulation/gens-2.15.5-r2; constraint set: [constraint(none,,[])].

---
Summary: portage://games-emulation/gens-2.15.5-r2: unsatisfied_constraints dependency on x11-libs/gtk+

Affected package: portage://games-emulation/gens-2.15.5-r2
Dependency: x11-libs/gtk+
Phases: [install,run]

Unsatisfiable constraint(s):
  x11-libs/gtk+-:2

Observed:
  portage-ng reports no available candidate satisfies the above constraint(s).
  Available versions in repo set (sample, first 3 of 3): [2.24.33-r3,2.24.33-r4,3.24.52]

Potential fix (suggestion):
  Review dependency metadata in portage://games-emulation/gens-2.15.5-r2; constraint set: [constraint(none,,[slot(2)])].