Python 为什么'；特殊额外要求：测试：工作？

我正在尝试使用中指定的

pip

和

setuptools

实现特殊的

：测试：

附加功能

我创建了以下

setup.py

：

#!/usr/bin/env python3
from setuptools import setup

setup(
    name='spam',
    version='0.0.0',
    tests_require=['requests'])

运行

/setup.py bdist_wheel

会给我一个包含以下

元数据.json

的控制盘：

{
  "name": "spam",
  "test_requires": [
    {
      "requires": [
        "requests"
      ]
    }
  ],
  "extensions": {
    "python.details": {
      "document_names": {
        "description": "DESCRIPTION.rst"
      }
    }
  },
  "summary": "UNKNOWN",
  "generator": "bdist_wheel (0.24.0)",
  "version": "0.0.0",
  "metadata_version": "2.0"
}

我希望能够通过指定额外的

：test:

来安装

测试所需的
。但是，这会得到以下输出：

$ pip install spam-0.0.0-cp34-cp34m-linux_x86_64.whl\[:test:\]
Exception:
Traceback (most recent call last):
  File "/tmp/5221/lib/python3.4/site-packages/pip/basecommand.py", line 232, in main
    status = self.run(options, args)
  File "/tmp/5221/lib/python3.4/site-packages/pip/commands/install.py", line 305, in run
    name, None, isolated=options.isolated_mode,
  File "/tmp/5221/lib/python3.4/site-packages/pip/req/req_install.py", line 179, in from_line
    isolated=isolated)
  File "/tmp/5221/lib/python3.4/site-packages/pip/req/req_install.py", line 52, in __init__
    req = pkg_resources.Requirement.parse(req)
  File "/tmp/5221/lib/python3.4/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2873, in parse
    reqs = list(parse_requirements(s))
  File "/tmp/5221/lib/python3.4/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2816, in parse_requirements
    DISTRO, CBRACKET, line, p, (1,), "'extra' name"
  File "/tmp/5221/lib/python3.4/site-packages/pip/_vendor/pkg_resources/__init__.py", line 2785, in scan_list
    raise ValueError(msg, line, "at", line[p:])
ValueError: ("Expected 'extra' name in", 'spam-0.0.0-cp34-cp34m-linux_x86_64.whl[:test:]', 'at', ':test:]')

使用
pip install-e.\[：test:\]

我使用的是Python2.7还是3.4并不重要。我使用最新的virtualenv（pip==6.0.6
，
setuptools==12.0.4
，
wheel==0.24.0
）

我做错了什么