Hello,  I'm still beginner for GuixSd.

I have installed epiphany but show error , missing hicolor-icon-theme.
I have installed hicolor-icon-theme. No error message but show bookmark icon only, other icons missing.

What is other icon-theme or another packages I need to install?

I think missing icon cache but gtk-update-icon-cache command is missing too then install gtk+-3.24.0. 

Why gtk+-3.24.0 package don't include gtk-update-icon-cache etc commands?