Source package openbabel-2.3.2-2 used by EPEL7 does not support ppc64le. A newer version supporting this architecture should be used instead.
What's the exact issue? Are there any error messages/logs? I wouldn't want to just blindly upgrade to whatever is in rawhide.
You are completely right to not blindly upgrade. I just tested again the openbabel build in ppc64le epel7 and it is succesful. I guess problem was coming from wxGTK package that have been corrected since. Sorry for the noise !