Question

以下行引发了Linux中的奇怪异常（几个Ubuntu 14.04安装和一个安装了所有更新的Arch linux安装）：

subprocess.call(['/home/vestnik/Development/test/python/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/venv/bin/pip','install','httpbin'])

python2.7：

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/subprocess.py", line 523, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/usr/lib/python2.7/subprocess.py", line 711, in __init__
    errread, errwrite)
  File "/usr/lib/python2.7/subprocess.py", line 1343, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory

python3.5：

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.5/subprocess.py", line 557, in call
    with Popen(*popenargs, **kwargs) as p:
  File "/usr/lib/python3.5/subprocess.py", line 947, in __init__
    restore_signals, start_new_session)
  File "/usr/lib/python3.5/subprocess.py", line 1551, in _execute_child
    raise child_exception_type(errno_num, err_msg)
FileNotFoundError: [Errno 2] No such file or directory: '/home/vestnik/Development/test/python/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/venv/bin/pip'

pip可执行文件我试图运行的是virtualenv bootstrap脚本创建的有效现有文件。当pip的路径长度变得大于120个字符（近似）时，会出现问题。如果我删除一个＆＃34; subdir＆＃34;路径中间的元素很有效。这个问题的原始来源是jenkins构建由于长工作空间名称而无法创建virtualenv。

子进程模块中的可执行路径长度是否存在任何限制（我还没有在函数文档中找到它），还是实现错误？有没有很好的方法来解决它？

Answer 1

当我试图通过bash在venv中调用pip时，我的解释器出错了。

问题的真正根源是shebang字符串长度限制（对接受的答案here的评论声称默认限制等于127字节）：

$ head -n1 /home/vestnik/Development/test/python/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/venv/bin/pip 
#!/home/vestnik/Development/test/python/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/venv/bin/python3.5
$ head -n1 /home/vestnik/Development/test/python/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/subdir/venv/bin/pip | wc -c
129

问题源不是子进程模块。它只产生令人困惑的错误。

以下代码有效：

subprocess.call([
    '/home/...lonl long venv path.../venv/bin/python3.5',
    '/home/...lonl long venv path.../venv/bin/pip',
    'install',
    'httpbin'
])

调用virtualenv捆绑的pip wuth subprocess.call在Linux上的venv目录的长路径上失败

1 个答案: