Check for new baseline results if we don't have any yet

In Ubuntu, we only fetch results on demand, so we might not
have seen the results yet.

Debian always fetches results at the beginning so has all the
data ready.

britney2/policies/autopkgtest.py

@@ -1228,7 +1228,21 @@ class AutopkgtestPolicy(BasePolicy):
         result_reference = [Result.NONE, None, '', 0]
         if self.options.adt_baseline == 'reference':
             try:
-                result_reference = self.test_results[REF_TRIG][src][arch]
+                try:
+                    result_reference = self.test_results[REF_TRIG][src][arch]
+                except KeyError:
+                    uses_swift = not self.options.adt_swift_url.startswith('file://')
+                    # Without swift or autopkgtest.db we don't expect new results
+                    if hasattr(self,'db'):
+                        self.logger.info('Checking for new results for %s/%s for trigger %s', src, arch, REF_TRIG)
+                        self.fetch_sqlite_results(src, arch)
+                    elif uses_swift:
+                        self.logger.info('Checking for new results for %s/%s for trigger %s', src, arch, REF_TRIG)
+                        self.fetch_swift_results(self.options.adt_swift_url, src, arch)
+
+                    # do we have one now?
+                    result_reference = self.test_results[REF_TRIG][src][arch]
+
                 self.logger.debug('Found result for src %s in reference: %s',
                                   src, result_reference[0].name)
             except KeyError: