--- a/cubicweb/server/test/unittest_serverctl.py	Mon Mar 06 13:15:51 2017 +0100
+++ b/cubicweb/server/test/unittest_serverctl.py	Mon Mar 06 15:22:16 2017 +0100
@@ -3,14 +3,19 @@
 
 from cubicweb import ExecutionError
 from cubicweb.devtools import testlib, ApptestConfiguration
-from cubicweb.server.serverctl import _local_dump, DBDumpCommand, SynchronizeSourceCommand
+from cubicweb.server.serverctl import DBDumpCommand, SynchronizeSourceCommand
 from cubicweb.server.serverconfig import ServerConfiguration
 
+
 class ServerCTLTC(testlib.CubicWebTC):
+
     def setUp(self):
         super(ServerCTLTC, self).setUp()
         self.orig_config_for = ServerConfiguration.config_for
-        config_for = lambda appid: ApptestConfiguration(appid, __file__)
+
+        def config_for(appid):
+            return ApptestConfiguration(appid, __file__)
+
         ServerConfiguration.config_for = staticmethod(config_for)
 
     def tearDown(self):

--- a/flake8-ok-files.txt	Mon Mar 06 13:15:51 2017 +0100
+++ b/flake8-ok-files.txt	Mon Mar 06 15:22:16 2017 +0100
@@ -47,6 +47,7 @@
 cubicweb/server/test/data-schema2sql/__init__.py
 cubicweb/server/test/unittest_checkintegrity.py
 cubicweb/server/test/unittest_ldapsource.py
+cubicweb/server/test/unittest_serverctl.py
 cubicweb/server/test/unittest_session.py
 cubicweb/server/test/unittest_rqlannotation.py
 cubicweb/sobjects/test/unittest_notification.py