As per $summary, with guile-2.2 (which Gentoo patches in "support" for), nearly every menu in the gschem GUI opens the About window rather than doing what the user expects.
Downgrading to guile-2.0.14-r3 (and rebuilding geda) solves this.
To quickly reproduce, start gschem with an empty document and hit 'f' 's' which should open the save dialog.
*** Bug 681768 has been marked as a duplicate of this bug. ***