I played around a bit and built it in mock and found several dependencies you didn't have in the spec file. You didn't provide the desktop file so I commented it out but I noticed it puts one in /etc/wbar.d so I'm not sure what it's for...

I can fix it up a bit more if you can provide more info.

https://www.dropbox.com/s/oh87uhv422z6kl3/wbar-2.3.4-1.fc28.src.rpm

Thanks,
Richard