Failure to install pylint when prompted to do so (Permission Denied)

[stewartadam]

Environment data

VS Code version: 1.181
Python Extension version: 0.8.0
Python Version: 2.7.10
OS and version: macOS 10.13.2

Actual behavior

Opening a .py file prompts to install pylint. Pylint installation fails.

Expected behavior

Pylint installation succeeds.

Steps to reproduce:

• Open VS Code
• Open a Python file
• Click on prompt to install pyline

Logs

/usr/bin/python -m pip install pylint
TARS:~ stewartadam$ /usr/bin/python -m pip install pylint
Collecting pylint
  Using cached pylint-1.7.4-py2.py3-none-any.whl
Requirement already satisfied: six in ./Library/Python/2.7/lib/python/site-packages (from pylint)
Collecting isort>=4.2.5 (from pylint)
  Using cached isort-4.2.15-py2.py3-none-any.whl
Collecting singledispatch; python_version < "3.4" (from pylint)
  Using cached singledispatch-3.4.0.3-py2.py3-none-any.whl
Collecting mccabe (from pylint)
  Using cached mccabe-0.6.1-py2.py3-none-any.whl
Collecting configparser; python_version == "2.7" (frompylint)
Collecting backports.functools-lru-cache; python_version == "2.7" (from pylint)
  Using cached backports.functools_lru_cache-1.4-py2.py3-none-any.whl
Collecting astroid>=1.5.1 (from pylint)
  Using cached astroid-1.5.3-py2.py3-none-any.whl
Collecting wrapt (from astroid>=1.5.1->pylint)
Requirement already satisfied: enum34>=1.1.3; python_version < "3.4" in ./Library/Python/2.7/lib/python/site-packages (from astroid>=1.5.1->pylint)
Collecting lazy-object-proxy (from astroid>=1.5.1->pylint)
Installing collected packages: isort, singledispatch, mccabe, configparser, backports.functools-lru-cache, wrapt, lazy-object-proxy, astroid, pylint
Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/usr/local/lib/python2.7/site-packages/pip/commands/install.py", line 342, in run
    prefix=options.prefix_path,
  File "/usr/local/lib/python2.7/site-packages/pip/req/req_set.py", line 784, in install
    **kwargs
  File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 851, in install
    self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
  File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 1064, in move_wheel_files
    isolated=self.isolated,
  File "/usr/local/lib/python2.7/site-packages/pip/wheel.py", line 345, in move_wheel_files
    clobber(source, lib_dir, True)
  File "/usr/local/lib/python2.7/site-packages/pip/wheel.py", line 316, in clobber
    ensure_dir(destdir)
  File "/usr/local/lib/python2.7/site-packages/pip/utils/__init__.py", line 83, in ensure_dir
    os.makedirs(path)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/os.py", line 157, in makedirs
    mkdir(name, mode)
OSError: [Errno 13] Permission denied: '/Library/Python/2.7/site-packages/isort'
TARS:~ stewartadam$

[stewartadam]

Note: I'm aware of other alternatives such as sudo or --user that can be used to install pylint, this issue is reported in that it should not fail for users by default.

[DonJayamanne]

I don't think sudo is a good option. If such an error appears, then IMHO its time for the user to start using a virtual environment. As for not displaying this error, I don't know its worth checking the user has permissions to install or not, if there's an error in pip install, then isn't that for the user to resolve.
I guess this all boils down to UX.

[MikhailArkhipov]

Users probably don't have install permissions by default or otherwise one app could silently install another. I'd expect this kind of hardening from OS similarly to what happens on devices.

Somewhat related microsoft/vscode#1614 and
https://github.com/jorangreef/sudo-prompt

[DonJayamanne]

@MikhailArkhipov sounds like a good solution. One hiccup we run the command in a terminal. Guess we'll have to change the way we install the packages.

[MikhailArkhipov]

OK, I can look into this

[esutton]

I think sudo-prompt would be a good solution.

I see many development package installers on macOS using something similar.

I think Xcode 9.2 is using this or something similar to request "helper" support.

[brettcannon]

I'm slowly starting to think we might want to offer to install a private copy of tools in the extension itself to avoid these kinds of issues.

[MikhailArkhipov]

Here is what I coded up (need to sort out stdout/err outputs)

[brettcannon]

I'm a little leery of supporting people installing into a sudo-protected Python installation as you almost never want to do that. We will need to discuss this a bit further before committing any code.

[DonJayamanne]

@MikhailArkhipov

#386 (comment)

With this approach, we might want to include the command thats being executed. The reason I've used the terminal is so users can see what's happening and tweek the command if need be.
E.g. I found that if they were behind a proxy, then we need to pass the proxy details to pip, who knows what we'd need in the future.

[MikhailArkhipov]

Generally addressed by 4372809. There is also #527 in works

[zzj0402]

--user doesn't help.

[brettcannon]

@zzj0402 if python3 -m pip install --user pylint fails when run in a terminal then there is an issue with your system and not the extension itself.