This "new copy" cannot copy classes like that:
class _AttributeString(str):
    """
    Simple string subclass to allow arbitrary attribute access.
    """
    @property
    def stdout(self):
        return str(self)

These classes can happen and, despite that it is possible to add setter to that classes to allow that new copy do this task, it is not the desirable behavour.

Exception occurred:
  File "/usr/lib/python2.7/site-packages/sphinx/util/nodes.py", line 302, in _new_copy
    newnode.line = self.line
AttributeError: can't set attribute
The full traceback has been saved in /usr/src/tmp/sphinx-err-D5RFSs.log, if you want to report the issue to the developers.
Please also report this if it was a user error, so that a better error messaDge can be provided next time.
A bug report can be filed in the tracker at <https://github.com/sphinx-doc/sphinx/issues>. Thanks!
error: Bad exit status from /usr/src/tmp/rpm-tmp.34537 (%build)

[#282038] DONE (try 12) del=python-module-sphinx