--- debderiver
+++ debderiver_patch6_2.py
@@ -183,15 +183,6 @@
         self._updates.append(upd)
 
     def _do(self, command):
-        """Execute a reprepro command."""
-
-        # TODO: replace this function with _do2, i.e. use subprocess
-        # instead of os.system.
-
-        os.system(' '.join(('reprepro --noskipold -Vb', self._base_path,
-            command)))
-
-    def _do2(self, command):
         """Execute a reprepro command with feedback."""
 
         return subprocess.Popen(['reprepro', '--noskipold', '-Vb',
@@ -206,7 +197,7 @@
             if os.path.isfile(p):
                 ext = f.split('.')[-1].lower()
                 if ext in ('deb', 'dsc', 'udeb'):
-                    self._do(' '.join(('include' + ext, suite, p)))
+                    self._do(['include' + ext, suite, p])
 
     def _include_thirdparty(self):
         """Recursively include third-party packages."""
@@ -241,9 +232,9 @@
                 command = ['-T', 'dsc', 'listfilter', dist.codename,
                         '($Source (==' + src_pkg + '), $Version (% *' +
                         self._op_sys.name.lower() + '*))']
-                if not self._do2(command):
+                if not self._do(command):
                     # Package version is not ours, it can be deleted.
-                    self._do(' '.join(('removesrc', dist.codename, src_pkg)))
+                    self._do(['removesrc', dist.codename, src_pkg])
 
     def _write_configuration(self):
         if os.path.isdir(self._conf_path):
@@ -350,8 +341,8 @@
         """Update the repository."""
 
         self._purge_purge_lists()
-        self._do('update')
-        self._do('processincoming all')
+        self._do(['update'])
+        self._do(['processincoming', 'all'])
         self._include_thirdparty()