Pytest在安装pytest-xdist后无法识别-n选项

Question

我已经在pytest工作环境上安装了pytest-xdist：

pip install pytest-xdist

我已经收到了这个输出

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...

此时，我已经尝试并行运行我的测试套件。

py.test -n 4

但是我收到了下面的输出

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

'py.test --version is‘的输出

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

而pytest-xdist实际上缺失了。

我哪里错了？谢谢。

Answer 1

和user2412166一样，我也遇到了同样的问题。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，我在系统上运行了一个严格的umask，默认情况下禁止对other用户的所有访问和对group用户的写访问：

$ umask
027

虽然这通常是一件好事，但偶尔也会给我带来麻烦。在此umask下通过pip3安装python-xdist

$ sudo pip3 install pytest-xdist

pip3中的...resulted禁止非超级用户进行读取和执行访问-最好只有我这样的超级用户

$ 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这样做没有错，但py.test是(...arguably!)在插件检测期间默默忽略而不是显式报告明显的权限问题是错误的。

通过递归地授予other用户对受影响的系统目录的读取和目录执行权限，可以很容易地修复此问题：

$ 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

证据就是命令行布丁：

$ 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

这样就清楚了不清楚之处，调试了buggy，并快速并行化了缓慢的测试。

Answer 2

我也有同样的问题。问题不在于版本。不知何故，py.test看不到xdist在哪里。以下是对我有效的方法：

pip install pytest --用户

pip安装pytest-xdist --user

导出路径=$HOME/.local/bin：$PATH

Answer 3

请尝试py.test --version并查看输出，其中解释了导入内容的位置，包括插件。很可能没有运行您认为正在运行的py.test。