Make run_mirror more verbose about failures.

When run_mirror fails to run pip install or downloads print the project
and branch that failed to make debugging problems easier.

Change-Id: I2fec996005010de0e1c6d72b026e09a1e1143acb
Reviewed-on: https://review.openstack.org/23614
Reviewed-by: Anita Kuno <akuno@lavabit.com>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Approved: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins
diff --git a/jeepyb/cmd/run_mirror.py b/jeepyb/cmd/run_mirror.py
index 9a21dd0..6062497 100644
--- a/jeepyb/cmd/run_mirror.py
+++ b/jeepyb/cmd/run_mirror.py
@@ -134,6 +134,8 @@
                 if DEBUG:
                     print(out)
                 if "\nSuccessfully installed " not in out:
+                    sys.stderr.write("Installing pip requires for %s:%s "
+                                     "failed." % (project, branch))
                     sys.stderr.write(out)
                     print("pip install did not indicate success")
                 else:
@@ -152,6 +154,8 @@
                     if DEBUG:
                         print(out)
                     if "\nSuccessfully downloaded " not in out:
+                        sys.stderr.write("Downloading pip requires for %s:%s "
+                                         "failed." % (project, branch))
                         sys.stderr.write(out)
                         print("pip install did not indicate success")
                     print("cached:\n%s" % freeze)