a defective build

[Matthias Clasen <matthias clasen gmail com>]

One thing that stands out when using the current repo is that icons
are missing. Symbolic icons, that is. The build seems to have produced
nothing of value:

$ ostree --repo=/ostree/repo ls -R `ostree --repo=/ostree/repo
rev-parse components/gnomeos-3.4/gnome-icon-theme-symbolic/i686` /
d02755 0 0      0 /
-00644 0 0    449 /_ostbuild-meta.json
d02755 0 0      0 /devel
d02755 0 0      0 /doc
d02755 0 0      0 /runtime