Pylint instance doesn't respect PYTHONPATH and/or source roots

kkew3 commented 5 years ago

Step 1: Are you in the right place?

This is highly related to https://github.com/leinardi/pylint-pycharm/issues/10, but it has been closed.

[x] I have verified there are no duplicate active or recent bugs, questions, or requests
[x] I have verified that I am using the latest version of the plugin.

Step 2: Describe your environment

Plugin version: v0.11.0
PyCharm/IDEA version: 2018.3.5 (Community Edition)
Pylint version: 2.3.1

Step 3: Describe the problem:

Pylint run by the plugin doesn't put source roots into PYTHONPATH. Therefore, all import statements involving project files trigger no-name-in-module error.

Steps to reproduce:

Create a new project under directory ${some_directory}/xxx, using virtualenv under ${some_directory}/xxx/rt; activate the virtualenv by cd ${some_directory}/xxx; . rt/bin/activate.
Install pylint: pip install pylint
Create directory ${some_directory}/xxx/src, and mark it as source root in pycharm. Create two files, ${some_directory}/xxx/src/utils.py, filled with def f(x): return x + 1, and ${some_directory}/xxx/src/hello.py, filled with import utils; def hello(n): print('hello:', utils.f(n)). (The code is written in one line for clarity. See the actual layout in screenshot below)
Run pylint plugin on ${some_directory}/xxx/src/hello.py.

Observed Results:

In terminal, under working directory ${some_directory}/xxx, with the virtualenv rt activated, run PYTHONPATH="$(pwd)/src" pylint src/hello.py. It doesn't report module 'utils' has no 'f' member. However, the Pylint plugin does report.
- Interestingly, the Pylint plugin stops reporting the error some time later. I haven't thought of a way to measure the time lapse.

Expected Results:

The plugin should not report module xxx has no yyy member in such case, and should behave the same as the terminal pylint.

Relevant Code:

src/hello.py
```
import utils
```

def greeting(n): print('hello:', utils.f(n))


* `src/utils.py`

```python
def f(x):
    return x + 1

Event Log: Yes there's exclamation mark around Event Log in the screenshot. However I removed the test project before I saw the comment about pasting the event log. I tend to believe the problem has been partially fixed. IMHO the scanning of source roots might not be done every time before running pylint. I also tested removing the mark source root on src. While pycharm inspection immediately underlines import utils in hello.py, there's no response from the pylint plugin (after it has stopped reporting the error).