[entropy.spm] when get_installed_package_metadata fails, raise KeyError and handle it

client/text_rescue.py

@@ -401,8 +401,11 @@ def _database_spmsync(entropy_client):
     spm_packages = Spm.get_installed_packages()
     installed_packages = []
     for spm_package in spm_packages:
-        pkg_counter = Spm.get_installed_package_metadata(spm_package,
-            "COUNTER")
+        try:
+            pkg_counter = Spm.get_installed_package_metadata(spm_package,
+                "COUNTER")
+        except KeyError:
+            continue
         try:
             pkg_counter = int(pkg_counter)
         except ValueError:

libraries/entropy/spm/plugins/interfaces/portage_plugin/__init__.py

@@ -396,7 +396,10 @@ class PortagePlugin(SpmPlugin):
         if root is None:
             root = etpConst['systemroot'] + os.path.sep
         vartree = self._get_portage_vartree(root = root)
-        return vartree.dbapi.aux_get(package, [key])[0]
+        try:
+            return vartree.dbapi.aux_get(package, [key])[0]
+        except KeyError: # make clear that we raise KeyError
+            raise
 
     def get_system_packages(self):
         """

libraries/entropy/spm/plugins/skel.py

@@ -176,6 +176,7 @@ class SpmPlugin(Singleton):
         @type root: string
         @return: package metadata value
         @rtype: string
+        @raise KeyError: if package is not available
         """
         raise NotImplementedError()