install error

[Tukali]

centos6 python2.6

when i run python setup.py install ,show it:

Processing html5lib-1.0.1.tar.gz
Running html5lib-1.0.1/setup.py -q bdist_egg --dist-dir /tmp/easy_install-2O6H6j/html5lib-1.0.1/egg-dist-tmp-qViNVM
Traceback (most recent call last):
File "setup.py", line 325, in
**extra
File "/usr/lib64/python2.6/distutils/core.py", line 152, in setup
dist.run_commands()
File "/usr/lib64/python2.6/distutils/dist.py", line 975, in run_commands
self.run_command(cmd)
File "/usr/lib64/python2.6/distutils/dist.py", line 995, in run_command
cmd_obj.run()
File "/usr/lib/python2.6/site-packages/setuptools/command/install.py", line 73, in run
self.do_egg_install()
File "/usr/lib/python2.6/site-packages/setuptools/command/install.py", line 101, in do_egg_install
cmd.run()
File "/usr/lib/python2.6/site-packages/setuptools/command/easy_install.py", line 236, in run
self.easy_install(spec, not self.no_deps)
File "/usr/lib/python2.6/site-packages/setuptools/command/easy_install.py", line 452, in easy_install
return self.install_item(None, spec, tmpdir, deps, True)
File "/usr/lib/python2.6/site-packages/setuptools/command/easy_install.py", line 504, in install_item
self.process_distribution(spec, dist, deps)
File "/usr/lib/python2.6/site-packages/setuptools/command/easy_install.py", line 545, in process_distribution
[requirement], self.local_index, self.easy_install
File "/usr/lib/python2.6/site-packages/pkg_resources.py", line 538, in resolve
dist = best[req.key] = env.best_match(req, self, installer)
File "/usr/lib/python2.6/site-packages/pkg_resources.py", line 780, in best_match
return self.obtain(req, installer) # try and download/install
File "/usr/lib/python2.6/site-packages/pkg_resources.py", line 792, in obtain
return installer(requirement)
File "/usr/lib/python2.6/site-packages/setuptools/command/easy_install.py", line 472, in easy_install
return self.install_item(spec, dist.location, tmpdir, deps)
File "/usr/lib/python2.6/site-packages/setuptools/command/easy_install.py", line 502, in install_item
dists = self.install_eggs(spec, download, tmpdir)
File "/usr/lib/python2.6/site-packages/setuptools/command/easy_install.py", line 681, in install_eggs
return self.build_and_install(setup_script, setup_base)
File "/usr/lib/python2.6/site-packages/setuptools/command/easy_install.py", line 958, in build_and_install
self.run_setup(setup_script, setup_base, args)
File "/usr/lib/python2.6/site-packages/setuptools/command/easy_install.py", line 947, in run_setup
run_setup(setup_script, args)
File "/usr/lib/python2.6/site-packages/setuptools/sandbox.py", line 29, in run_setup
lambda: execfile(
File "/usr/lib/python2.6/site-packages/setuptools/sandbox.py", line 70, in run
return func()
File "/usr/lib/python2.6/site-packages/setuptools/sandbox.py", line 31, in
{'file':setup_script, 'name':'main'}
File "setup.py", line 54, in
paths = os.environ['PATH'].split(':')
AttributeError: 'module' object has no attribute 'MarkerEvaluation'

what can i do ?