utils/scanpypi: restore modules search path in case of error

We extend the modules search path to be able to load the package
metadata. Currently, it is only restored when loading those
succeeded, not when it failed.

Restore it to its previous state also in case of error, to avoid
leaking the path further.

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 69400611b2940c2b5cd8bb587b359562eeb95abb)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

utils/scanpypi

@@ -296,23 +296,25 @@ class BuildrootPackage():
         current_dir = os.getcwd()
         os.chdir(self.tmp_extract)
         sys.path.insert(0, self.tmp_extract)
-        s_file, s_path, s_desc = imp.find_module('setup', [self.tmp_extract])
-        imp.load_module('__main__', s_file, s_path, s_desc)
-        if self.metadata_name in self.setup_args:
-            pass
-        elif self.metadata_name.replace('_', '-') in self.setup_args:
-            self.metadata_name = self.metadata_name.replace('_', '-')
-        elif self.metadata_name.replace('-', '_') in self.setup_args:
-            self.metadata_name = self.metadata_name.replace('-', '_')
         try:
-            self.setup_metadata = self.setup_args[self.metadata_name]
-        except KeyError:
-            # This means setup was not called
-            print('ERROR: Could not determine package metadata for {pkg}.\n'
-                  .format(pkg=self.real_name))
-            raise
-        os.chdir(current_dir)
-        sys.path.remove(self.tmp_extract)
+            s_file, s_path, s_desc = imp.find_module('setup', [self.tmp_extract])
+            imp.load_module('__main__', s_file, s_path, s_desc)
+            if self.metadata_name in self.setup_args:
+                pass
+            elif self.metadata_name.replace('_', '-') in self.setup_args:
+                self.metadata_name = self.metadata_name.replace('_', '-')
+            elif self.metadata_name.replace('-', '_') in self.setup_args:
+                self.metadata_name = self.metadata_name.replace('-', '_')
+            try:
+                self.setup_metadata = self.setup_args[self.metadata_name]
+            except KeyError:
+                # This means setup was not called
+                print('ERROR: Could not determine package metadata for {pkg}.\n'
+                      .format(pkg=self.real_name))
+                raise
+        finally:
+            os.chdir(current_dir)
+            sys.path.remove(self.tmp_extract)
 
     def get_requirements(self, pkg_folder):
         """