commit d9579e983f5a196e7ed155035c0e8283c4f9f904
Author: Thomas Woerner <twoerner@redhat.com>
Date:   Mon Aug 15 11:51:32 2016 +0200

    firewall.client: Generate new DBUS_ERROR if SystemBus can not be aquired
    
    This happens for example in change roots. The SystemBus() call in slip.dbus
    fails and also the dbus.SystemBus() call.
    
    New error code: DBUS_ERROR

diff --git a/src/firewall/client.py b/src/firewall/client.py
index 177a74e..5875df2 100644
--- a/src/firewall/client.py
+++ b/src/firewall/client.py
@@ -2207,8 +2207,13 @@ class FirewallClient(object):
                 self.bus = slip.dbus.SystemBus()
                 self.bus.default_timeout = None
             except Exception:
-                print("Not using slip")
-                self.bus = dbus.SystemBus()
+                try:
+                    self.bus = dbus.SystemBus()
+                except dbus.exceptions.DBusException as e:
+                    raise FirewallError(errors.DBUS_ERROR,
+                                        e.get_dbus_message())
+                else:
+                    print("Not using slip.dbus")
         else:
             self.bus = bus
 
diff --git a/src/firewall/errors.py b/src/firewall/errors.py
index d939864..34d1d18 100644
--- a/src/firewall/errors.py
+++ b/src/firewall/errors.py
@@ -44,6 +44,7 @@ IPSET_WITH_TIMEOUT  =   32
 BUILTIN_IPSET       =   33
 ALREADY_SET         =   34
 MISSING_IMPORT      =   35
+DBUS_ERROR          =   36
 
 INVALID_ACTION      =  100
 INVALID_SERVICE     =  101

commit 937eb926a1ec6f09a3ff825296927e9964232204
Author: Thomas Woerner <twoerner@redhat.com>
Date:   Mon Aug 15 11:55:19 2016 +0200

    firewall-cmd, firewallctl: Gracefully fail if SystemBus can not be aquired

diff --git a/src/firewall-cmd b/src/firewall-cmd
index 3cf3059..75513c7 100755
--- a/src/firewall-cmd
+++ b/src/firewall-cmd
@@ -911,7 +911,13 @@ if a.help:
     sys.exit(0)
 
 zone = a.zone
-fw = FirewallClient()
+
+try:
+    fw = FirewallClient()
+except FirewallError as msg:
+    code = FirewallError.get_code(str(msg))
+    cmd.print_and_exit("Error: %s" % msg, code)
+
 fw.setExceptionHandler(cmd.exception_handler)
 if fw.connected == False:
     if a.state:
commit 63f4f46180d5fe26a68ef6517d2f612fb74a3254
Author: Thomas Woerner <twoerner@redhat.com>
Date:   Mon Aug 15 11:57:06 2016 +0200

    firewall.core.fw_nm: Ignore NetworkManager if NM.Client connect fails
    
    This happens for example in change roots.

diff --git a/src/firewall/core/fw_nm.py b/src/firewall/core/fw_nm.py
index 5f8c8f8..c958e9a 100644
--- a/src/firewall/core/fw_nm.py
+++ b/src/firewall/core/fw_nm.py
@@ -27,6 +27,7 @@ __all__ = [ "check_nm_imported", "nm_is_imported",
             "nm_get_bus_name", "nm_get_dbus_interface" ]
 
 import gi
+from gi.repository import GLib
 try:
     gi.require_version('NM', '1.0')
 except ValueError:
@@ -35,8 +36,7 @@ else:
     try:
         from gi.repository import NM
         _nm_imported = True
-    except (ImportError, ValueError):
-        NetworkManager = None
+    except (ImportError, ValueError, GLib.Error):
         _nm_imported = False
 
 from firewall import errors