Pylint is executed in an Unicode-incompatible way.

[amyodov]

(The problem has been spotted under OS X version of Atom and pylint from pip3, but may be applicable to other OSes).

To properly display the warnings/errors in Python lines containing the Unicode (UTF-8) strings, Pylint must be executed with proper locale for stdout. In command line, it is usually something like LANG=en_US.UTF-8 pylint, but the LANG part is usually omitted as it has some reasonable UTF-8 defaults.
When pylint is executed from under Atom/OS X, it seems though it is executed with presumed LANG=C. This causes any line containing UTF-8 characters and attempted to be reported by pylint, to break pylint, miserably. After pylint fails (with traceback), this traceback is promoted to linter-pylint and reported with huge red traceback popup; the overall result is that under OS X, if the Python code has any pylint-mentionable line which contains UTF-8 symbols, linter-pylint breaks.

This issue has been reported to pylint as well, at pylint-dev/pylint#859

Example

(Partially quotes the pylint-dev/pylint#859 )

Let's take the following file test.py (note the unnecessary space before the closing bracket of print()), and open it in Atom:

if __name__ == '__main__':
    print("Привет, мир (Hello world in Russian)" )

If we open it in Atom which has linter-pylint available, this is what we receive:

This traceback can be reproduced from the command line, if we lint the file using LANG=C python3.5 which pylint test.py command line. But there will be no traceback, if we lint the file using LANG=UTF-8 python3.5 which pylint test.py.

[Arcanemagus]

Ah, yet another example of OSX breaking everything with their "Let's launch GUI applications with a blank environment" idea...

If you close all instances of Atom, and then launch Atom from a terminal (atom .), do you still see this breakage?

[amyodov]

Arcanemagus, sorry for slow response.
When launching Atom from a terminal, it, predictably, doesn't have this issue.

[Arcanemagus]

Marking this as a bug for now, I'm not sure if this is the proper place to fix this or if this should be escalated up to sb-exec, which is what eventually handles running pylint.