From e63a191bbad3fb97396cacc25f800baa930a8ab2 Mon Sep 17 00:00:00 2001
From: Chenxiong Qi <cqi@redhat.com>
Date: Sep 01 2016 13:23:09 +0000
Subject: Show useful message when command new fails


Fix #84

Signed-off-by: Chenxiong Qi <cqi@redhat.com>

---

diff --git a/src/pyrpkg/__init__.py b/src/pyrpkg/__init__.py
index 98433f6..abfd2d2 100644
--- a/src/pyrpkg/__init__.py
+++ b/src/pyrpkg/__init__.py
@@ -1626,7 +1626,10 @@ class Commands(object):
         """Return changes in a repo since the last tag"""
 
         # Find the latest tag
-        tag = self.repo.git.describe('--tags', '--abbrev=0')
+        try:
+            tag = self.repo.git.describe('--tags', '--abbrev=0')
+        except git.exc.GitCommandError:
+            raise rpkgError('Cannot get changes because there are no tags in this repo.')
         # Now get the diff
         self.log.debug('Diffing from tag %s' % tag)
         return self.repo.git.diff('-M', tag)