The meld-3.17.0-2.fc26 RPM has both Python 2 and Python 3 dependencies:
$ rpm -qRp meld-3.17.0-2.fc24.noarch.rpm
python(abi) = 3.5
This software supports Python 3 , and the dependencies are already ported (python3-dbus, python3-cairo, python3-gobject). Is there any reason to keep Python 2 dependencies?
Except in very special circumstances, there is no need for one package
to drag in both Python stacks. There is a section on Requires in the Python RPM Porting Guide  which covers this issue.
Please split your package, or remove the stray dependencies.
If anything is unclear, or if you need any kind of assistance, you can
ask on IRC (#fedora-python on Freenode), or reply here. We'll be happy
to help investigating or fixing this issue!
thanks very much for reporting this. There is no specific reason for keeping dependencies to Python 2, seems I've just overlooked something. I've built a new release which adjusts the dependencies you've mentioned:
I'd be glad if you'd had a look if that looks better now, obviously my Python packaging know-how doesn't seem that advanced… :-)
thank you very much for a prompt response.
The change looks good, closing the bug.