builds: set missing start/end time for node errors

When a build failed with NODE_FAILURE, the reported result doesn't have a
start/end time.

Change-Id: I3323347e6c91932690dac998c68eaf4a0fea2e5f

zuul/driver/sql/sqlreporter.py

@@ -14,6 +14,7 @@
 
 import datetime
 import logging
+import time
 import voluptuous as v
 
 from zuul.reporter import BaseReporter
@@ -65,6 +66,9 @@ class SQLReporter(BaseReporter):
                     # stats about builds. It doesn't understand how to store
                     # information about the change.
                     continue
+                # Ensure end_time is defined
+                if not build.end_time:
+                    build.end_time = time.time()
 
                 (result, url) = item.formatJobResult(job)
 

zuul/model.py

@@ -2219,6 +2219,8 @@ class QueueItem(object):
 
     def setNodeRequestFailure(self, job):
         fakebuild = Build(job, None)
+        fakebuild.start_time = time.time()
+        fakebuild.end_time = time.time()
         self.addBuild(fakebuild)
         fakebuild.result = 'NODE_FAILURE'
         self.setResult(fakebuild)