$ mkdir foo
$ touch foo/__init__.py
$ echo "from .bar.extensionmodule import f" > foo/a.py
$ mkdir foo/bar
$ touch foo/bar/__init__.py
$ pylint foo -r n --disable=C,W --ignored-modules=foo.bar.extensionmodule
No config file found, using default configuration
************* Module foo.a
E:  1, 0: No name 'extensionmodule' in module 'foo.bar' (no-name-in-module)
E:  1, 0: Unable to import 'bar.extensionmodule' (import-error)

mic@mic ~ $ pylint --version
No config file found, using default configuration
pylint 1.4.3,
astroid 1.3.6, common 1.0.1
Python 3.4.3+ (default, Jun  2 2015, 14:09:35)
[GCC 4.9.2]