ytdl-org/youtube-dl · error · ExtractorError

message

Error message

message

What it means

Raised by the PacktPub extractor's login helper when the auth-v1 token endpoint returns HTTP 400/401/404. The extractor reads the response body and re-raises the server's own 'message' field as an expected ExtractorError. The literal 'message' in the catalog is the format source: the actual text (e.g. 'Invalid username or password') comes from Packt's API.

Source

Thrown at youtube_dl/extractor/packtpub.py:65

    }]
    _NETRC_MACHINE = 'packtpub'
    _TOKEN = None

    def _real_initialize(self):
        username, password = self._get_login_info()
        if username is None:
            return
        try:
            self._TOKEN = self._download_json(
                'https://services.packtpub.com/auth-v1/users/tokens', None,
                'Downloading Authorization Token', data=json.dumps({
                    'username': username,
                    'password': password,
                }).encode())['data']['access']
        except ExtractorError as e:
            if isinstance(e.cause, compat_HTTPError) and e.cause.code in (400, 401, 404):
                message = self._parse_json(e.cause.read().decode(), None)['message']
                raise ExtractorError(message, expected=True)
            raise

    def _real_extract(self, url):
        course_id, chapter_id, video_id, display_id = re.match(self._VALID_URL, url).groups()

        headers = {}
        if self._TOKEN:
            headers['Authorization'] = 'Bearer ' + self._TOKEN
        try:
            video_url = self._download_json(
                'https://services.packtpub.com/products-v1/products/%s/%s/%s' % (course_id, chapter_id, video_id), video_id,
                'Downloading JSON video', headers=headers)['data']
        except ExtractorError as e:
            if isinstance(e.cause, compat_HTTPError) and e.cause.code == 400:
                self.raise_login_required('This video is locked')
            raise

        # TODO: find a better way to avoid duplicating course requests

View on GitHub (pinned to 956b8c5855)

Solutions

  1. Verify the Packt credentials by logging in at packtpub.com in a browser, then correct --username/---password or .netrc
  2. If credentials are correct, suspect the auth-v1 endpoint is gone — update youtube-dl/yt-dlp to a version with the fixed Packt extractor
  3. Test extraction anonymously (no credentials) since some free content works without a token

Example fix

# before
youtube_dl --username me@example.com --password 'wrong' 'https://www.packtpub.com/application-development/some-video'
# after
youtube_dl --netrc 'https://www.packtpub.com/application-development/some-video'  # with verified 'machine packtpub login me@example.com password correct' in ~/.netrc
Defensive patterns

Strategy: validation

Validate before calling

// Verify credentials work before batch extraction
curl -s -o /dev/null -w '%{http_code}' -X POST https://services.packtpub.com/auth-v1/users/tokens -d '{"username":"me@example.com","password":"hunter2"}'
// 200 → credentials fine; 400/401/404 → fix before invoking yt-dlp

Try / catch

try:
    ydl.extract_info(url)
except ExtractorError as e:
    if e.expected:  # server-supplied auth message
        print('Packt login rejected:', str(e))

Prevention

When it happens

Trigger: Calling PacktPub extraction with --username/--password (or netrc) where services.packtpub.com/auth-v1/users/tokens rejects the credentials with 400/401/404; or when the auth endpoint moves/changes shape (404 body may not even be JSON, which would instead cause a parse error).

Common situations: Wrong or expired Packt login in .netrc; ebook-claim-only accounts lacking video access; API v1 being retired by Packt so the 404 path triggers; password containing characters mangled by JSON encoding.

Related errors

AI-assisted analysis of ytdl-org/youtube-dl@956b8c5855 (2026-08-14). Data as JSON: /api/errors/143aa3b8be9c828f. Report an issue: GitHub.