error: option --cython not a unique prefix

[ArthurPeabody]

That's what I get when I try to run

python setup.py build_ext --inplace --cython

Compiling gbinder.pyx because it changed.
[1/1] Cythonizing gbinder.pyx
usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
or: setup.py --help [cmd1 cmd2 ...]
or: setup.py --help-commands
or: setup.py cmd --help

error: option --cython not a unique prefix