SyntaxError: '<' operator not allowed in environment markers

Question

Under python 2.7, I want to install mock-2.0.0, and got the following error:

Marker evaluation failed, see the following error.  For more information see: http://docs.openstack.org/developer/pbr/compatibility.html#evaluate-marker
ERROR:root:Error parsing
Traceback (most recent call last):
  File "/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pbr/core.py", line 96, in pbr
    attrs = util.cfg_to_args(path, dist.script_args)
  File "/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pbr/util.py", line 261, in cfg_to_args
    kwargs = setup_cfg_to_setup_kwargs(config, script_args)
  File "/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pbr/util.py", line 455, in setup_cfg_to_setup_kwargs
    if pkg_resources.evaluate_marker('(%s)' % env_marker):
  File "/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pkg_resources/__init__.py", line 1515, in evaluate_marker
    return cls.interpret(parser.expr(text).totuple(1)[1])
  File "/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pkg_resources/__init__.py", line 1549, in interpret
    return op(nodelist)
  File "/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pkg_resources/__init__.py", line 1463, in atom
    return cls.interpret(nodelist[2])
  File "/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pkg_resources/__init__.py", line 1549, in interpret
    return op(nodelist)
  File "/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pkg_resources/__init__.py", line 1484, in comparison
    raise SyntaxError(msg)
SyntaxError: '<' operator not allowed in environment markers
error in setup command: Error parsing /histor/kang/yangpc/soft/Python/Python_packages/mock-2.0.0/setup.cfg: SyntaxError: '<' operator not allowed in environment markers

After a while googling, I got the hints that this error was produced by older version of setuptools (discussion 1 and discussion 2).

The content of setup.cfg file is:

[metadata]
name = mock
summary = Rolling backport of unittest.mock for all Pythons
home-page = https://github.com/testing-cabal/mock
description-file = README.rst
author = Testing Cabal
author-email = testing-in-python@lists.idyll.org
classifier = 
        Development Status :: 5 - Production/Stable
        Environment :: Console
        Intended Audience :: Developers
        License :: OSI Approved :: BSD License
        Operating System :: OS Independent
        Programming Language :: Python
        Programming Language :: Python :: 2
        Programming Language :: Python :: 2.6
        Programming Language :: Python :: 2.7
        Programming Language :: Python :: 3
        Programming Language :: Python :: 3.2
        Programming Language :: Python :: 3.3
        Programming Language :: Python :: 3.4
        Programming Language :: Python :: 3.5
        Programming Language :: Python :: Implementation :: CPython
        Programming Language :: Python :: Implementation :: Jython
        Programming Language :: Python :: Implementation :: PyPy
        Topic :: Software Development :: Libraries
        Topic :: Software Development :: Libraries :: Python Modules
        Topic :: Software Development :: Testing
keyword = 
        testing, test, mock, mocking, unittest, patching, stubs, fakes, doubles

[extras]
test = 
        unittest2>=1.1.0
docs = 
        jinja2<2.7:python_version<"3.3" and python_version>="3"
        Pygments<2:python_version<"3.3" and python_version>="3"
        sphinx<1.3:python_version<"3.3" and python_version>="3"
        sphinx:python_version<"3" or python_version>="3.3"

[files]
packages = mock

[bdist_wheel]
universal = 1

[egg_info]
tag_build = 
tag_date = 0
tag_svn_revision = 0

However, After testing setuptools version 15.2, 27.3.0, 38.0.0 and the latest 40.2.0, the error remain. I have no idea how to debug this problem now.

All the installation of the python packages were performed using

python setup.py install --prefix=/histor/kang/yangpc/soft/Python/python2.7/

Thanks!

I have tried the following test

1. using pip
1.1 pip install  mock==2.0.0
/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pip-7.0.0.dev0-py2.7.egg/pip/_vendor/requests/packages/urllib3/util/ssl_.py:79: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
Collecting mock==2.0.0
/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pip-7.0.0.dev0-py2.7.egg/pip/_vendor/requests/packages/urllib3/util/ssl_.py:79: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pip-7.0.0.dev0-py2.7.egg/pip/_vendor/requests/packages/urllib3/util/ssl_.py:79: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
  Could not find a version that satisfies the requirement mock==2.0.0 (from versions: )
  No matching distribution found for mock==2.0.0

1.2 pip install mock
/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pip-7.0.0.dev0-py2.7.egg/pip/_vendor/requests/packages/urllib3/util/ssl_.py:79: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
Collecting mock
/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pip-7.0.0.dev0-py2.7.egg/pip/_vendor/requests/packages/urllib3/util/ssl_.py:79: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
/histor/kang/yangpc/soft/Python/python2.7/lib/python2.7/site-packages/pip-7.0.0.dev0-py2.7.egg/pip/_vendor/requests/packages/urllib3/util/ssl_.py:79: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
  Could not find a version that satisfies the requirement mock (from versions: )
  No matching distribution found for mock

This invoked another question, which I haven't found a solution.

update

This problem has been resolved by updating python from 2.7 to 2.7.15 and reinstall all the depended packages.

Thank you all!

It might help if you show the install command that you used. — Bram Vanroy, Sep 03 '18 at 08:49
Hi @BramVanroy, thank you for pointing out this lack of information, I have updated the content of the question and added the installation command. — pengchy, Sep 03 '18 at 08:58
@pengchy still not quite enough. You should show contents of `setup.cfg` in this case, as the error is coming from there. — matejcik, Sep 03 '18 at 09:12
more constructively: why do you install this way, as opposed to using `pip`? e.g., `pip install mock==2.0.0` — matejcik, Sep 03 '18 at 09:12
thanks for the updates. please also try `pip install mock`, without the version specifier -- unless you actually need mock v2.0.0 — matejcik, Sep 03 '18 at 09:53

score 0 · Answer 1 · answered Jan 05 '21 at 12:29

0

I had 2 versions of python installed on my centos 7.9. python2.7 and `python3.6.

pip threw me the above error pip3 did succeed.

e.g.
pip install mock ## failed.

pip3 install mock ##Succeeded

answered Jan 05 '21 at 12:29

Kishor Pawar

3,386
3
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SyntaxError: '<' operator not allowed in environment markers

1 Answers1