Cannot find module if source file is a symbolic link

[suhlatwork]

Somewhere between versions 1.5.5 and 1.7.1 the behaviour concerning modules using symbolic links to install files in the module directory has changed. Running pylint on such a module gives the following error:

$ pylint pyMyTool
No config file found, using default configuration
Traceback (most recent call last):
  File "/XXX/.local/bin/pylint", line 11, in <module>
    sys.exit(run_pylint())
  File "/XXX/.local/lib/python2.7/site-packages/pylint/__init__.py", line 13, in run_pylint
    Run(sys.argv[1:])
  File "/XXX/.local/lib/python2.7/site-packages/pylint/lint.py", line 1300, in __init__
    linter.check(args)
  File "/XXX/.local/lib/python2.7/site-packages/pylint/lint.py", line 726, in check
    self._do_check(files_or_modules)
  File "/XXX/.local/lib/python2.7/site-packages/pylint/lint.py", line 837, in _do_check
    for descr in self.expand_files(files_or_modules):
  File "/XXX/.local/lib/python2.7/site-packages/pylint/lint.py", line 869, in expand_files
    self.config.black_list_re)
  File "/XXX/.local/lib/python2.7/site-packages/pylint/utils.py", line 894, in expand_modules
    modpath = _modpath_from_file(subfilepath, is_namespace)
  File "/XXX/.local/lib/python2.7/site-packages/pylint/utils.py", line 833, in _modpath_from_file
    return modutils.modpath_from_file_with_callback(filename, is_package_cb=_is_package_cb)
  File "/XXX/.local/lib/python2.7/site-packages/astroid/modutils.py", line 310, in modpath_from_file_with_callback
    filename, ', \n'.join(sys.path)))
ImportError: Unable to find module for /tmp/yyy/py/git/pyBinding/module/_func.py in /tmp/yyy/py,
.,
/XXX/.local/bin,
/tmp/yyy/py/install/pyLib,
/opt/rh/devtoolset-3/root/usr/lib64/python2.6/site-packages,
/opt/rh/devtoolset-3/root/usr/lib/python2.6/site-packages,
/opt/rh/python27/root/usr/lib64/python27.zip,
/opt/rh/python27/root/usr/lib64/python2.7,
/opt/rh/python27/root/usr/lib64/python2.7/plat-linux2,
/opt/rh/python27/root/usr/lib64/python2.7/lib-tk,
/opt/rh/python27/root/usr/lib64/python2.7/lib-old,
/opt/rh/python27/root/usr/lib64/python2.7/lib-dynload,
/XXX/.local/lib/python2.7/site-packages,
/opt/rh/python27/root/usr/lib64/python2.7/site-packages,
/opt/rh/python27/root/usr/lib/python2.7/site-packages,
/XXX/.local/lib/python2.7/site-packages/astroid/brain

Steps to reproduce

Consider the following directory structure:

/tmp/yyy/py/install/pyLib/pyMyTool/
    __init__.py ->../../../git/pyBinding/module/__init__.py (symbolic link)
    _func.py -> ../../../git/pyBinding/module/_func.py (symbolic link)
/tmp/yyy/py/git/pyBinding/module/
    __init__.py
    _func.py

with __init__.py containing:

from _func import func

and _func.py containing:

def func():
    return 1

The directory /tmp/yyy/py/install/pyLib is included in the environment variable PYTHONPATH. Importing the module pyMyTool in Python works and has the expected result:

$ python
Python 2.7.5 (default, Jun  5 2014, 14:38:05)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pyMyTool
>>> pyMyTool.func()
1
>>>

Current behavior

Running pylint pyMyTool prints the aforementioned error message.

Expected behavior

Running pylint pyMyTool should run its tests.

pylint --version output

$ pylint --version
No config file found, using default configuration
pylint 1.7.1,
astroid 1.5.2
Python 2.7.5 (default, Jun  5 2014, 14:38:05)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-4)]

Please let me know in case you need additional information.

[christianmlong]

I think this is related to the change made in pylint-dev/astroid@cda9dc4

I'm getting the same problem when one of my python modules is actually a symlink, on macOS High Sierra, Python 2.7.14

I changed modutils.py line 290 back to what it was before cda9dc4, and that fixed the problem of Pylint not being able to find the symlink.

diff --git a/astroid/modutils.py b/astroid/modutils.py
index 83d0ba7..6e23da8 100644
--- a/astroid/modutils.py
+++ b/astroid/modutils.py
@@ -287,7 +287,7 @@ def check_modpath_has_init(path, mod_path):

 def modpath_from_file_with_callback(filename, extrapath=None, is_package_cb=None):
     filename = _path_from_filename(filename)
-    filename = os.path.realpath(os.path.expanduser(filename))
+    filename = os.path.abspath(filename)
     base = os.path.splitext(filename)[0]

     if extrapath is not None:

[ColCarroll]

Any fix for this in the meantime? (in particular, should I check with astroid if we can help fix there?)

[Pluckerpluck]

This is still a bug right?

[PCManticore]

@Pluckerpluck I presume so, the issue hasn't been closed or worked on lately.

[wandering007]

@Pluckerpluck I am also faced with this issue for pylint 2.3.1.

[jadchaar]

This seems to be an issue with the latest version of pylint:

pylint 2.5.0
astroid 2.4.0
Python 3.7.7 (default, Mar 10 2020, 15:43:33) 
[Clang 11.0.0 (clang-1100.0.33.17)]

Symlinks and pylint worked fine for our team on pylint 2.4.x