We have an optional package for PyX-0.10 (recent versions are 0.14). After installing it pip stops working with the message like
Traceback (most recent call last):
File "/home/sc_serv/sage/local/bin/pip", line 5, in <module>
from pkg_resources import load_entry_point
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 2912, in <module>
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 2898, in _call_aside
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 2925, in _initialize_master_working_set
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 633, in _build_master
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 626, in __init__
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 682, in add_entry
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 1956, in find_on_path
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 2343, in from_location
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 2660, in _reload_version
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 2308, in _version_from_file
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 2476, in _get_metadata
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 1847, in get_metadata_lines
File "build/bdist.linux-x86_64/egg/pkg_resources/__init__.py", line 1842, in get_metadata
File "/home/sc_serv/sage/local/lib/python/codecs.py", line 302, in decode
(result, consumed) = self._buffer_decode(data, self.errors, final)
UnicodeDecodeError: 'utf8' codec can't decode byte 0xf6 in position 165: invalid start byte
which seems to be due to author's name with non-Latin characters.
Installing PyX through pip does not work for some reason, but I think it should be removed from optional packages as it breaks pip which is way more important.