I get the following error:
dirname: missing operand
Try 'dirname --help' for more information.

(acroread:11314): Gtk-WARNING **: Unable to locate theme engine in module_path: "oxygen-gtk",

(acroread:11314): Gtk-WARNING **: Unable to locate theme engine in module_path: "oxygen-gtk",

(acroread:11314): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-can-change-accels after class was initialised

(acroread:11314): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-menu-popup-delay after class was initialised

(acroread:11314): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-menu-popdown-delay after class was initialised

(acroread:11314): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-label-select-on-focus after class was initialised

(acroread:11314): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-button-images after class was initialised

(acroread:11314): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-menu-bar-popup-delay after class was initialised

(acroread:11314): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-entry-select-on-focus after class was initialised

(acroread:11314): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-entry-password-hint-timeout after class was initialised

(acroread:11314): GLib-GObject-WARNING **: Attempt to add property GtkSettings::gtk-scrolled-window-placement after class was initialised

Any ideas?

easy solution would be to backup home folder and install sabayon again with version that works.

I would rather not go the who re-installation route if I can possible help it.

have you tried installing "oxygen-gtk"?
and searching google for that error?

Yes and yes, it was the first thing I did. Turned out that I only needed to update oxygen-gtk and the error seemed to be one that was solved a few years ago and hadn't really cropped up again.