I'm trying to re-record one of the pages in the key_mobile_sites page set but I'm hitting this error. This worked fine about a week ago. I'm running this command from src/tools/perf:

./record_wpr --browser=android-system-chrome --story=key_mobile_sites_smooth_page_set --story-filter=Wikipedia

And here's the output:

Your system python's version is less than 2.7.9. For best recording results, please run record_wpr with Python version 2.7.9 or after (See https://github.com/chromium/web-page-replay/issues/73 for more information).
For instructions on how to upgrade Python on Ubuntu 14.04, see:
http://mbless.de/blog/2016/01/09/upgrade-to-python-2711-on-ubuntu-1404-lts.html
=== BUS 1 ===
1: Device 1 (ID 1d6b:0002 Linux Foundation 2.0 root hub)
1:1: Device 31 (ID 0409:005a NEC Corp. HighSpeed Hub)
1:1:3: Device 32 (ID 046d:c016 Logitech, Inc. Optical Wheel Mouse)
1:1:4: Device 33 (ID 03f0:0024 Hewlett-Packard KU-0316 Keyboard)
1:3: Device 2 (ID 1050:0211 Yubico.com Gnubby)
1:6: Device 34 (ID 18d1:4ee7 Google Inc. )
1:7: Device 4 (ID 8087:0a2b Intel Corp. )
1:8: Device 6 (ID 04f2:b5c1 Chicony Electronics Co., Ltd )
1:9: Device 9 (ID 138a:0090 Validity Sensors, Inc. )
=== BUS 2 ===
1: Device 1 (ID 1d6b:0003 Linux Foundation 3.0 root hub)
WARNING:root:Cannot find path for chrome_stable on platform android_n_armeabi-v7a. Falling back to android_armeabi-v7a.
[ RUN      ] Wikipedia (1 tab)
[       OK ] Wikipedia (1 tab) (19202 ms)
[ RUN      ] Wikipedia (1 tab) - delayed scroll start
[       OK ] Wikipedia (1 tab) - delayed scroll start (17955 ms)
[  PASSED  ] 2 tests.


Traceback (most recent call last):
  <module> at /home/bokan/chrome/src/tools/perf/record_wpr:40
    sys.exit(record_wpr.Main(environment=config))
  Main at /home/bokan/chrome/src/third_party/catapult/telemetry/telemetry/record_wpr.py:312
    wpr_recorder.HandleResults(results, args.upload)
  HandleResults at /home/bokan/chrome/src/third_party/catapult/telemetry/telemetry/record_wpr.py:262
    target_platform=self._record_page_test.platform)
  AddRecordedStories at /home/bokan/chrome/src/third_party/catapult/telemetry/telemetry/wpr/archive_info.py:164
    (target_wpr_file, target_wpr_file_path) = self._NextWprFileName()
  _NextWprFileName at /home/bokan/chrome/src/third_party/catapult/telemetry/telemetry/wpr/archive_info.py:229
    raise Exception('Illegal wpr file name ' + wpr_file)
Exception: Illegal wpr file name key_mobile_sites_000.wpr

Locals:
  base           : None
  extension      : 'wprgo'
  highest_number : -1
  match          : None
  p              : u'DEFAULT'
  pattern        : '(?P<BASE>.*)_(?P<NUMBER>[0-9]+).wprgo'
  story          : u'http://m.espn.go.com/nhl/rankings'
  wpr_file       : u'key_mobile_sites_000.wpr'
  wpr_files      : [u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_009.wpr', u'key_mobile_sites_004.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_si ... e_sites_007.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_002.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_009.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_002.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_002.wpr', u'key_mobile_sites_000.wpr', u'key_mobile_sites_001.wpr', u'key_mobile_sites_008.wpr'] (truncated)