starting the bot with bootstrap_retries -1 fails startup

[xmatthias]

Steps to Reproduce

Use the below script with python-telegram-bot 22.4

import logging
import os

from telegram import Update
from telegram.ext import Application, ApplicationBuilder, CommandHandler, ContextTypes


LOGFORMAT = "%(asctime)s - %(name)s - %(levelname)s - %(message)s"
logging.basicConfig(
    level=logging.DEBUG,
    format=LOGFORMAT,
)

logger = logging.getLogger(__name__)
# logger.setLevel(logging.DEBUG)

token = os.environ.get('TELEGRAM_TOKEN')

# logger.debug("Creating telegram application")

application = Application.builder().token(token).build()


async def start(update: Update, context: ContextTypes.DEFAULT_TYPE):
    await context.bot.send_message(
        chat_id=update.effective_chat.id, text="I'm a bot, please talk to me!"
    )


start_handler = CommandHandler("start", start)
application.add_handler(start_handler)
application.run_polling(
    bootstrap_retries=-1,
)

The key is bootstrap_retries=-1 - which causes startup to be retried forever (even though the action already worked).

Expected behaviour

the application starts, /start responds with the expected response.

This worked with 22.3 - and fails with 22.4 - running into an endless loop.

Actual behaviour

Endless loop - of "This application is already initialized".
The bot doesn't respond to any command (it's never starting to poll)

Operating System

linux

Version of Python, python-telegram-bot & dependencies

python-telegram-bot 22.4 (2023.7-7837-g16117e5b6)
Bot API 9.2
Python 3.13.7 (main, Aug 28 2025, 17:07:40) [Clang 20.1.4 ]

Relevant log output

2025-09-21 08:56:28,844 - telegram.ext.ExtBot - DEBUG - Set Bot API URL: https://api.telegram.org/bot546065661:AAGSqjM2F3Zajs_HpiZY5LAYfD3AWmaGM3Y
2025-09-21 08:56:28,845 - telegram.ext.ExtBot - DEBUG - Set Bot API File URL: https://api.telegram.org/file/bot546065661:AAGSqjM2F3Zajs_HpiZY5LAYfD3AWmaGM3Y
2025-09-21 08:56:28,845 - __main__ - INFO - Starting polling
2025-09-21 08:56:28,845 - asyncio - DEBUG - Using selector: EpollSelector
2025-09-21 08:56:28,845 - telegram.ext - DEBUG - Network Retry Loop (Bootstrap Initialize Application): Starting
2025-09-21 08:56:28,845 - telegram.ext.ExtBot - DEBUG - Calling Bot API endpoint `getMe` with parameters `{}`
2025-09-21 08:56:28,848 - httpcore.connection - DEBUG - connect_tcp.started host='api.telegram.org' port=443 local_address=None timeout=5.0 socket_options=None
2025-09-21 08:56:28,886 - httpcore.connection - DEBUG - connect_tcp.complete return_value=<httpcore._backends.anyio.AnyIOStream object at 0x7f7f2397a510>
2025-09-21 08:56:28,887 - httpcore.connection - DEBUG - start_tls.started ssl_context=<ssl.SSLContext object at 0x7f7f23956210> server_hostname='api.telegram.org' timeout=5.0
2025-09-21 08:56:28,927 - httpcore.connection - DEBUG - start_tls.complete return_value=<httpcore._backends.anyio.AnyIOStream object at 0x7f7f23972490>
2025-09-21 08:56:28,927 - httpcore.http11 - DEBUG - send_request_headers.started request=<Request [b'POST']>
2025-09-21 08:56:28,928 - httpcore.http11 - DEBUG - send_request_headers.complete
2025-09-21 08:56:28,928 - httpcore.http11 - DEBUG - send_request_body.started request=<Request [b'POST']>
2025-09-21 08:56:28,928 - httpcore.http11 - DEBUG - send_request_body.complete
2025-09-21 08:56:28,928 - httpcore.http11 - DEBUG - receive_response_headers.started request=<Request [b'POST']>
2025-09-21 08:56:28,965 - httpcore.http11 - DEBUG - receive_response_headers.complete return_value=(b'HTTP/1.1', 200, b'OK', [(b'Server', b'nginx/1.18.0'), (b'Date', b'Sun, 21 Sep 2025 06:56:28 GMT'), (b'Content-Type', b'application/json'), (b'Content-Length', b'261'), (b'Connection', b'keep-alive'), (b'Strict-Transport-Security', b'max-age=31536000; includeSubDomains; preload'), (b'Access-Control-Allow-Origin', b'*'), (b'Access-Control-Allow-Methods', b'GET, POST, OPTIONS'), (b'Access-Control-Expose-Headers', b'Content-Length,Content-Type,Date,Server,Connection')])
2025-09-21 08:56:28,966 - httpx - INFO - HTTP Request: POST https://api.telegram.org/bot546065661:AAGSqjM2F3Zajs_HpiZY5LAYfD3AWmaGM3Y/getMe "HTTP/1.1 200 OK"
2025-09-21 08:56:28,967 - httpcore.http11 - DEBUG - receive_response_body.started request=<Request [b'POST']>
2025-09-21 08:56:28,967 - httpcore.http11 - DEBUG - receive_response_body.complete
2025-09-21 08:56:28,967 - httpcore.http11 - DEBUG - response_closed.started
2025-09-21 08:56:28,967 - httpcore.http11 - DEBUG - response_closed.complete
2025-09-21 08:56:28,968 - telegram.ext.ExtBot - DEBUG - Call to Bot API endpoint `getMe` finished with return value `{'id': 546065661, 'is_bot': True, 'first_name': 'freqtrad_test', 'username': 'xmatt_freq_test_bot', 'can_join_groups': True, 'can_read_all_group_messages': False, 'supports_inline_queries': False, 'can_connect_to_business': False, 'has_main_web_app': False}`
2025-09-21 08:56:28,968 - telegram.ext.ExtBot - DEBUG - This Bot is already initialized.
2025-09-21 08:56:29,969 - telegram.ext.Application - DEBUG - This Application is already initialized.
2025-09-21 08:56:30,971 - telegram.ext.Application - DEBUG - This Application is already initialized.
2025-09-21 08:56:31,972 - telegram.ext.Application - DEBUG - This Application is already initialized.

# Pressed ctrl+c here - it would continue like this forever!

2025-09-21 08:56:32,355 - telegram.ext.Application - DEBUG - Application received stop signal. Shutting down.
2025-09-21 08:56:32,356 - httpcore.connection - DEBUG - close.started
2025-09-21 08:56:32,356 - httpcore.connection - DEBUG - close.complete
2025-09-21 08:56:32,356 - telegram.ext.ExtBot - DEBUG - This Bot is already shut down. Returning.
2025-09-21 08:56:32,356 - telegram.ext.Updater - DEBUG - Shut down of Updater complete

Additional Context

This is most likely caused by failing to break out of the below loop if boostrap_retries is set to -1 (which sets infinite_loop to True).

Because of this - the bot fails to exit network_retry loop() even if the actual action failed.
I think expected behavior here is to have the bot to retry indefinitely if the action fails - but not retry indefinitely independent of the outcome of the action.

python-telegram-bot/src/telegram/ext/_utils/networkloop.py

Lines 120 to 126 in 14f8e89

	while effective_is_running():
	try:
	await do_action()
	if not infinite_loop:
	_LOGGER.debug("%s Action succeeded. Stopping loop.", log_prefix)
	break
	except RetryAfter as exc:

---

python-telegram-bot/src/telegram/ext/_application.py

Lines 792 to 803 in 14f8e89

	bootstrap_retries (:obj:`int`, optional): Whether the bootstrapping phase
	(calling :meth:`initialize` and the boostrapping of
	:meth:`telegram.ext.Updater.start_polling`)
	will retry on failures on the Telegram server.
	* < 0 - retry indefinitely
	* 0 - no retries (default)
	* > 0 - retry up to X times
	.. versionchanged:: 21.11
	The default value will be changed to from ``-1`` to ``0``. Indefinite retries
	during bootstrapping are not recommended.

The docstring explicitly mentions this as supported ("< 0 - retry indefinitely") - but as not recommended.

I can understand this is not recommended - but it should either be marked as not supported entirely (fail on startup?) - or should not result in an endless loop.

[Bibo-Joshi]

Hey thanks for raising the issue. That looks like a valid finding. Since you have already analyzed the issue, would you like to send a pr for fixing yourself?

[xmatthias]

no thanks.
I'd prefer if someone with more knowledge about internals will fix this...