Do not crash when searching for missing groups in Antergos repository…

… database

src/download/metalink.py

@@ -330,10 +330,8 @@ def build_download_queue(alpm, args=None):
 
     antdb = [db for db in handle.get_syncdbs() if 'antergos' == db.name]
     antdb = antdb[0]
+
     one_repo_groups_names = ['cinnamon', 'mate', 'mate-extra']
-
-    #one_repo_groups = [antdb.read_grp(one_repo_group)
-    #                   for one_repo_group in one_repo_groups_names]
     one_repo_groups = []
     for one_repo_group_name in one_repo_groups_names:
         grp = antdb.read_grp(one_repo_group_name)

src/pacman/pac.py

@@ -266,13 +266,22 @@ def install(self, pkgs, conflicts=None, options=None):
         # have to ensure we don't clobber the priority of the repos.
         repos = OrderedDict()
         repo_order = []
-        one_repo_groups = ['cinnamon', 'mate', 'mate-extra']
         db_match = [db for db in self.handle.get_syncdbs()
                     if 'antergos' == db.name]
         antdb = OrderedDict()
         antdb['antergos'] = db_match[0]
-        one_repo_groups = [antdb['antergos'].read_grp(one_repo_group)
-                           for one_repo_group in one_repo_groups]
+
+        one_repo_groups_names = ['cinnamon', 'mate', 'mate-extra']
+        one_repo_groups = []
+        for one_repo_group_name in one_repo_groups_names:
+            grp = antdb['antergos'].read_grp(one_repo_group_name)
+            if not grp:
+                grp = ['None', []]
+                logging.warning(
+                    "Error reading group '%s' from the antergos repo db",
+                    one_repo_group_name)
+            one_repo_groups.append(grp)
+
         one_repo_pkgs = {pkg for one_repo_group in one_repo_groups
                          for pkg in one_repo_group[1] if one_repo_group}