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

Calculating dependencies ... done!
Dependency resolution took 0.86 s (backtrack: 0/20).


!!! The ebuild selected to satisfy "sci-electronics/geda" has unmet requirements.
- sci-electronics/geda-1.10.2-r102::gentoo USE="nls -debug -doc" GUILE_SINGLE_TARGET="-2-2"

  The following REQUIRED_USE flag constraints are unsatisfied:
    guile_single_target_2-2

  The above constraints are a subset of the following complete expression:
    exactly-one-of ( guile_single_target_2-2 )

(dependency required by "sci-electronics/geda-suite-20171223-r2::gentoo" [ebuild])
(dependency required by "=sci-electronics/geda-suite-20171223-r2" [argument])