Add morphlib.Error and make local repo cache exceptions be based on it

This way, cliapp will automatically print an error message, rather
than a stack trace.

1 files changed, 8 insertions, 0 deletions

diff --git a/morphlib/__init__.py b/morphlib/__init__.py
index d110296d..121c9431 100644
--- a/morphlib/__init__.py
+++ b/morphlib/__init__.py
@@ -17,6 +17,14 @@
 '''Baserock library.'''
 
 
+import cliapp
+
+
+class Error(cliapp.AppException):
+
+    '''Base for all morph exceptions that cause user-visible messages.'''
+
+
 import artifact
 import artifactresolver
 import bins