Bug 1325216 - Restore the ability to pull artifacts from try jobs for local artifact builds. r=mshal

MozReview-Commit-ID: Kl5n9coYdJY

--HG--
extra : rebase_source : b882e3d17cc44d8a22c83491ee0c6c6688d3b01a

python/mozbuild/mozbuild/artifacts.py

@@ -1044,7 +1044,8 @@ class Artifacts(object):
                   'revision': revision},
                  'Will only accept artifacts from a pushhead at {revision} '
                  '(matched revset "{revset}").')
-        pushheads = [(list(CANDIDATE_TREES), revision)]
+        # Include try in our search to allow pulling from a specific push.
+        pushheads = [(list(CANDIDATE_TREES) + ['try'], revision)]
         return self._install_from_hg_pushheads(pushheads, distdir)
 
     def install_from(self, source, distdir):