Log command output if it can't be parsed

If `xcrun altool` returns data that can't be parsed or correctly
interpreted, rethrow with the actual data so that the data is logged.
This way, the next time it happens we can see what bad data is being
returned and will be able to make the notarization tool more robust.

Bug: none
Change-Id: Icb4ceaa669b37ef9cdda7d8abd8f478532108fe0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2147816Reviewed-by: Robert Sesek <rsesek@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758533}

chrome/installer/mac/signing/notarize.py

@@ -43,10 +43,16 @@ def submit(path, config):
     if config.notary_asc_provider is not None:
         command.extend(['--asc-provider', config.notary_asc_provider])
     output = commands.run_command_output(command)
-    plist = plistlib.loads(output)
-    uuid = plist['notarization-upload']['RequestUUID']
-    logger.info('Submitted %s for notarization, request UUID: %s.', path, uuid)
-    return uuid
+    try:
+        plist = plistlib.loads(output)
+        uuid = plist['notarization-upload']['RequestUUID']
+        logger.info('Submitted %s for notarization, request UUID: %s.', path,
+                    uuid)
+        return uuid
+    except:
+        raise NotarizationError(
+            'xcrun altool returned output that could not be parsed: {}'.format(
+                output))
 
 
 def wait_for_results(uuids, config):