diff --git a/setup.py b/setup.py
index 43284dd990847f69fce31837c17746dae9a6a58c..85424fe5e1a1174bca41146f383daa5856ee3f65 100644
--- a/setup.py
+++ b/setup.py
@@ -13,7 +13,7 @@ setup(
     name="xbob.extension",
     version="0.3.0a0",
     description="Helps projects building Python/C++ extensions for Bob",
-    license="GPLv3",
+    license="BSD",
     author='Andre Anjos',
     author_email='andre.anjos@idiap.ch',
     long_description=open('README.rst').read(),
@@ -36,7 +36,7 @@ setup(
     classifiers = [
       'Development Status :: 3 - Alpha',
       'Intended Audience :: Developers',
-      'License :: OSI Approved :: GNU General Public License v3 (GPLv3)',
+      'License :: OSI Approved :: BSD License',
       'Natural Language :: English',
       'Programming Language :: Python',
       'Programming Language :: Python :: 3',
diff --git a/xbob/extension/pkgconfig.py b/xbob/extension/pkgconfig.py
index 16397ebcc6282fe18f1bfcc84f370fd9d0a1ba09..63610c2cf7c20b05cb0e9b9665d34ed1284dae62 100644
--- a/xbob/extension/pkgconfig.py
+++ b/xbob/extension/pkgconfig.py
@@ -27,7 +27,7 @@ def uniq(seq, idfun=None):
 
 def call_pkgconfig(cmd, paths=None):
   """Runs a command as a subprocess and raises if that does not work
-  
+
   Returns the exit status, stdout and stderr.
   """
 
@@ -79,7 +79,7 @@ class pkgconfig:
        >>> glibc.library_directories() # doctest: SKIP
        ['/usr/lib']
 
-  If the package does not exist, a RuntimeError is raised. All calls to any 
+  If the package does not exist, a RuntimeError is raised. All calls to any
   methods of a ``pkgconfig`` object are translated into a subprocess call that
   queries for that specific information. If ``pkg-config`` fails, a
   RuntimeError is raised.
@@ -97,7 +97,7 @@ class pkgconfig:
     extra_paths
       Search paths to be added to the environment's PKG_CONFIG_PATH to search
       for packages.
-    
+
     Equivalent command line version:
 
     .. code-block:: sh
@@ -160,7 +160,7 @@ class pkgconfig:
 
   def include_directories(self):
     """Returns a pre-processed list containing include directories.
-    
+
     Equivalent command line version:
 
     .. code-block:: sh
@@ -171,7 +171,7 @@ class pkgconfig:
 
     status, stdout, stderr = self.__xcall__(['--cflags-only-I'])
 
-    if status != 0: 
+    if status != 0:
       raise RuntimeError("error querying --cflags-only-I for package `%s': %s" % (self.package, stderr))
 
     retval = []
@@ -182,7 +182,7 @@ class pkgconfig:
 
   def cflags_other(self):
     """Returns a pre-processed dictionary containing compilation options.
-   
+
     Equivalent command line version:
 
     .. code-block:: sh
@@ -190,13 +190,13 @@ class pkgconfig:
        $ PKG_CONFIG_PATH=<paths> pkg-config --cflags-only-other <name>
 
     The returned dictionary contains two entries ``extra_compile_args`` and
-    ``define_macros``. The ``define_macros`` entries are ready for deployment 
+    ``define_macros``. The ``define_macros`` entries are ready for deployment
     in the ``setup()`` function of your package.
     """
 
     status, stdout, stderr = self.__xcall__(['--cflags-only-other'])
 
-    if status != 0: 
+    if status != 0:
       raise RuntimeError("error querying --cflags-only-other for package `%s': %s" % (self.package, stderr))
 
     flag_map = {
@@ -227,7 +227,7 @@ class pkgconfig:
 
   def libraries(self):
     """Returns a pre-processed list containing libraries to link against
-    
+
     Equivalent command line version:
 
     .. code-block:: sh
@@ -238,7 +238,7 @@ class pkgconfig:
 
     status, stdout, stderr = self.__xcall__(['--libs-only-l'])
 
-    if status != 0: 
+    if status != 0:
       raise RuntimeError("error querying --libs-only-l for package `%s': %s" % (self.package, stderr))
 
     retval = []
@@ -249,7 +249,7 @@ class pkgconfig:
 
   def library_directories(self):
     """Returns a pre-processed list containing library directories.
-    
+
     Equivalent command line version:
 
     .. code-block:: sh
@@ -260,7 +260,7 @@ class pkgconfig:
 
     status, stdout, stderr = self.__xcall__(['--libs-only-L'])
 
-    if status != 0: 
+    if status != 0:
       raise RuntimeError("error querying --libs-only-L for package `%s': %s" % (self.package, stderr))
 
     retval = []
@@ -271,7 +271,7 @@ class pkgconfig:
 
   def extra_link_args(self):
     """Returns a pre-processed list containing extra link arguments.
-    
+
     Equivalent command line version:
 
     .. code-block:: sh
@@ -289,13 +289,13 @@ class pkgconfig:
 
   def variable_names(self):
     """Returns a list with all variable names know to this package
-    
+
     Equivalent command line version:
 
     .. code-block:: sh
 
        $ PKG_CONFIG_PATH=<paths> pkg-config --print-variables <name>
-    
+
     """
 
     status, stdout, stderr = self.__xcall__(['--print-variables'])
@@ -307,7 +307,7 @@ class pkgconfig:
 
   def variable(self, name):
     """Returns a variable with a specific name (if it exists)
-    
+
     Equivalent command line version:
 
     .. code-block:: sh