Fix some pylint

Signed-off-by: Cole Robinson <crobinso@redhat.com>

tests/test_cli.py

@@ -455,7 +455,7 @@ class App(object):
         self._add(cat, args, None, check_success=True, **kwargs)
     def add_invalid(self, cat, args, **kwargs):
         if "grep" not in kwargs:
-            raise Exception("grep= must be passed for add_invalid")
+            raise RuntimeError("grep= must be passed for add_invalid")
         self._add(cat, args, None, check_success=False, **kwargs)
     def add_compare(self, cat, args, compbase, **kwargs):
         self._add(cat, args, compbase,

tests/test_xmlparse.py

@@ -1183,7 +1183,7 @@ def testUnknownEmulatorDomcapsLookup(monkeypatch):
     """
 
     seen = False
-    def fake_build_from_params(conn, emulator, arch, machine, hvtype):
+    def fake_build_from_params(conn, emulator, arch, machine, _hvtype):
         nonlocal seen
         seen = True
         assert arch == "mips"

virtinst/cli.py

@@ -1276,7 +1276,7 @@ class _InitClass(type):
     but without giving us an explicit dep on python 3.6
 
     """
-    def __new__(cls, *args, **kwargs):
+    def __new__(cls, *args, **kwargs):  # pylint: disable=bad-mcs-classmethod-argument
         if len(args) != 3:
             return super().__new__(cls, *args)  # pragma: no cover
         dummy = kwargs

virtinst/guest.py

@@ -636,7 +636,7 @@ class Guest(XMLBuilder):
                 capsinfo = self.lookup_capsinfo()
             except Exception:
                 log.exception("Error fetching machine list for alias "
-                              "resolution, assuming mismatch");
+                              "resolution, assuming mismatch")
                 return False
             if capsinfo.is_machine_alias(self.os.machine, domcaps.machine):
                 return True
@@ -743,7 +743,7 @@ class Guest(XMLBuilder):
             if original_machine_type.startswith(prefix):
                 self.os.machine = machine_alias
                 return
-        raise Exception("Don't know how to refresh machine type '%s'" %
+        raise RuntimeError("Don't know how to refresh machine type '%s'" %
                 original_machine_type)
 
     def set_smbios_serial_cloudinit(self):

virtinst/xmlbuilder.py

@@ -54,7 +54,7 @@ class XMLManualAction(object):
             val = self.xpath_value
         else:
             if "=" not in str(xpath):
-                raise Exception(
+                raise ValueError(
                     "%s: Setting xpath must be in the form of XPATH=VALUE" %
                     xpath)
             xpath, val = xpath.rsplit("=", 1)