balsa is unthemed

[Tony Nelson]

The balsa email program draws unthemed on my system after upgrading to
F20.  Actually, the adwaita theme works, but none of the other themes
do.  I get no complaints from Gtk in .xsession-errors or journalctl when
changing themes.  Other programs are OK.

Does anyone else see this or know what it is?

How to debug it?