Comment 6 for bug 1659336

> any specific reason why the real index.theme file from the hicolor icon theme is not installed for GTK3-based trunk builds, and instead a empty one is created?

Specific reason: Yes
I simply put in the fix from 0.92.x. As there is no "/share/icons/hicolor" in devlibs someone started to use an empty index.theme at some point. As this caused crashes with devlibs64 I added a dummy file which worked fine for both.

Good reason: No
You're completely right that we could include the correct file instead of using a dummy, especially if it causes stock icons to break (I wasn't aware of such an issue).
Do you know if we have to install all the empty folders too, or can we safely omit them and only install the index.theme?