Make sure to upgrade using pip2, not pip3 (which was my default)
pip2 install lektor --upgrade
Updating packages in /Users/shawn/Library/Caches/Lektor/packages/bfb65f8eb2370fc030d55007ed233188 for project
Collecting lektor-markdown-highlighter==0.1
Using cached lektor_markdown_highlighter-0.1-py2-none-any.whl
Collecting Pygments (from lektor-markdown-highlighter==0.1)
Using cached Pygments-2.1.3-py2.py3-none-any.whl
Installing collected packages: Pygments, lektor-markdown-highlighter
Exception:
Traceback (most recent call last):
File "/usr/local/lib/python2.7/site-packages/pip/basecommand.py", line 215, in main
status = self.run(options, args)
File "/usr/local/lib/python2.7/site-packages/pip/commands/install.py", line 317, in run
prefix=options.prefix_path,
File "/usr/local/lib/python2.7/site-packages/pip/req/req_set.py", line 742, in install
**kwargs
File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 831, in install
self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 1032, in move_wheel_files
isolated=self.isolated,
File "/usr/local/lib/python2.7/site-packages/pip/wheel.py", line 247, in move_wheel_files
prefix=prefix,
File "/usr/local/lib/python2.7/site-packages/pip/locations.py", line 153, in distutils_scheme
i.finalize_options()
File "/usr/local/Cellar/python/2.7.12/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/command/install.py", line 264, in finalize_options
"must supply either home or prefix/exec-prefix -- not both"
DistutilsOptionError: must supply either home or prefix/exec-prefix -- not both