python – Pytest在安装pytest-xdist后无法识别-n选项

我已经在一个正常工作的pytest环境中安装了pytest-xdist：

pip install pytest-xdist

我收到了这个输出

Downloading/unpacking pytest-xdist
  Downloading pytest-xdist-1.10.tar.gz
  Running setup.py egg_info for package pytest-xdist

    no prevIoUsly-included directories found matching '.hg'
Downloading/unpacking execnet>=1.1 (from pytest-xdist)
  Downloading execnet-1.2.0.tar.gz (163kB): 163kB downloaded
  Running setup.py egg_info for package execnet

    warning: no files found matching 'conftest.py'
Requirement already satisfied (use --upgrade to upgrade): pytest>=2.4.2 in /Users/sal/Documents/code/Python/VirtualEnv/Spring/lib/python2.7/site-packages (from pytest-xdist)
Requirement already satisfied (use --upgrade to upgrade): py>=1.4.20 in /Users/sal/Documents/code/Python/VirtualEnv/Spring/lib/python2.7/site-packages (from pytest>=2.4.2->pytest-xdist)
Installing collected packages: pytest-xdist, execnet
  Running setup.py install for pytest-xdist

    no prevIoUsly-included directories found matching '.hg'
  Running setup.py install for execnet

    warning: no files found matching 'conftest.py'
Successfully installed pytest-xdist execnet
Cleaning up...

在这一点上,我试图并行运行我的测试套件

py.test -n 4

但我收到了这个输出

usage: py.test [options] [file_or_dir] [file_or_dir] [...]
py.test: error: unrecognized arguments: -n

输出’py.test –version’

This is pytest version 2.6.2, imported from /Users/sal/Documents/code/Python/VirtualEnv/Spring/lib/python2.7/site-packages/pytest.pyc
setuptools registered plugins:
  pytest-capturelog-0.7 at /Users/sal/Documents/code/Python/VirtualEnv/Spring/lib/python2.7/site-packages/pytest_capturelog.pyc
  pytest-contextfixture-0.1.1 at /Users/sal/Documents/code/Python/VirtualEnv/Spring/lib/python2.7/site-packages/pytest_contextfixture.pyc
  pytest-cov-1.7.0 at /Users/sal/Documents/code/Python/VirtualEnv/Spring/lib/python2.7/site-packages/pytest_cov.pyc
  pytest-django-2.6.2 at /Users/sal/Documents/code/Python/VirtualEnv/Spring/lib/python2.7/site-packages/pytest_django/plugin.pyc
  pytest-pydev-0.1 at /Users/sal/Documents/code/Python/VirtualEnv/Spring/lib/python2.7/site-packages/pytest_pydev.pyc
  pytest-runFailed-0.3 at /Users/sal/Documents/code/Python/VirtualEnv/Spring/lib/python2.7/site-packages/pytest_runFailed.pyc

和pytest-xdist实际上是缺失的.

我错了什么？谢谢.

解决方法:

像user2412166一样,我遇到了同样的问题.与user2412166不同,我的解决方案是放宽pip3安装的xdist和pytest_xdist-1.14.dist-info系统目录的权限.

一些背景故事：为了安全起见,我在我的系统上运行严格的umask,禁止所有访问其他用户并默认写入组用户的权限：

$umask
027

虽然这通常是一件好事,但偶尔也会让我遇到麻烦.在这个umask下通过pip3安装python-xdist：

$sudo pip3 install pytest-xdist

…导致pip3禁止对非超级用户的读取和执行访问 – 最好只有我：

$ls -l /usr/lib64/python3.4/site-packages/xdist
drwxr-x---   3 root root 4.0K 2016-04-10 01:19 xdist/
$ls -l /usr/lib64/python3.4/site-packages/pytest_xdist-1.14.dist-info
drwxr-x---   3 root root 4.0K 2016-04-10 01:19 xdist/

虽然pip3这样做并没有错,但是py.test在安静地忽略而不是在插件检测期间明确报告明显的权限问题时(…可能！)是错误的.

通过递归授予其他用户对受影响的系统目录的读取和目录执行权限,可以轻松解决这个问题：

$chmod -R o+rX /usr/lib64/python3.4/site-packages/xdist
$chmod -R o+rX /usr/lib64/python3.4/site-packages/pytest_xdist-1.14.dist-info

证明是命令行布丁：

$ls -l /usr/lib64/python3.4/site-packages/xdist
drwxr-xr-x   3 root root 4.0K 2016-04-10 01:19 xdist/
$ls -l /usr/lib64/python3.4/site-packages/pytest_xdist-1.14.dist-info
drwxr-xr-x   3 root root 4.0K 2016-04-10 01:19 xdist/
$py.test --version
This is pytest version 2.8.7, imported from /usr/lib64/python3.4/site-packages/pytest.py
setuptools registered plugins:
  pytest-xdist-1.14 at /usr/lib64/python3.4/site-packages/xdist/looponfail.py
  pytest-xdist-1.14 at /usr/lib64/python3.4/site-packages/xdist/plugin.py
  pytest-xdist-1.14 at /usr/lib64/python3.4/site-packages/xdist/Boxed.py

因此,目前尚不明确,调试错误,慢速测试快速并行化.