Value error on "az ad sp create-for-rbac"

[azgabur]

Describe the bug

On running az ad sp create-for-rbac --name "name" I get following crash.

Related command

az ad sp create-for-rbac

Errors

The command failed with an unexpected error. Here is the traceback:
badly formed help string
Traceback (most recent call last):
File "/usr/lib/python3.14/argparse.py", line 1744, in _check_help
formatter._expand_help(action)
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 672, in _expand_help
return help_string % params
~~~~~~~~~~~~^~~~~~~~
ValueError: unsupported format character 'Y' (0x59) at index 77

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/opt/azure-cli/lib/python3.14/site-packages/knack/cli.py", line 233, in invoke
cmd_result = self.invocation.execute(args)
File "/opt/azure-cli/lib/python3.14/site-packages/azure/cli/core/commands/init.py", line 570, in execute
self.parser.load_command_table(self.commands_loader)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
File "/opt/azure-cli/lib/python3.14/site-packages/azure/cli/core/parser.py", line 129, in load_command_table
param = AzCliCommandParser._add_argument(command_parser, arg)
File "/opt/azure-cli/lib/python3.14/site-packages/knack/parser.py", line 64, in _add_argument
return obj.add_argument(*scrubbed_options_list, **argparse_options)
~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 1558, in add_argument
self._check_help(action)
~~~~~~~~~~~~~~~~^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 1746, in _check_help
raise ValueError('badly formed help string') from exc
ValueError: badly formed help string

Issue script & Debug output

cli.knack.cli: Command arguments: ['ad', 'sp', 'create-for-rbac', '--debug']
cli.knack.cli: init debug log:
Enable color in terminal.
cli.knack.cli: Event: Cli.PreExecute []
cli.knack.cli: Event: CommandParser.OnGlobalArgumentsCreate [<function CLILogging.on_global_arguments at 0x7f1364a8d380>, <function OutputProducer.on_global_arguments at 0x7f13649a7530>, <function CLIQuery.on_global_arguments at 0x7f13649e9dd0>]
cli.knack.cli: Event: CommandInvoker.OnPreCommandTableCreate []
cli.azure.cli.core: Modules found from index for 'ad': ['azure.cli.command_modules.role']
cli.azure.cli.core: Loading command modules:
cli.azure.cli.core: Name Load Time Groups Commands
cli.azure.cli.core: role 0.007 17 62
cli.azure.cli.core: Total (1) 0.007 17 62
cli.azure.cli.core: Loaded 17 groups, 62 commands.
cli.azure.cli.core: Found a match in the command table.
cli.azure.cli.core: Raw command : ad sp create-for-rbac
cli.azure.cli.core: Command table: ad sp create
cli.azure.cli.core: remaining : for-rbac
cli.knack.cli: Event: CommandInvoker.OnPreCommandTableTruncate [<function AzCliLogging.init_command_file_logging at 0x7f13639a7ed0>]
cli.azure.cli.core.azlogging: metadata file logging enabled - writing logs to '/home/azgabur/.azure/commands/2026-02-23.16-19-17.ad_sp_create-for-rbac.299119.log'.
az_command_data_logger: command args: ad sp create-for-rbac --debug
cli.knack.cli: Event: CommandInvoker.OnPreArgumentLoad [<function register_global_subscription_argument..add_subscription_parameter at 0x7f13637d16f0>]
cli.knack.cli: Event: CommandInvoker.OnPostArgumentLoad []
cli.knack.cli: Event: CommandInvoker.OnPostCommandTableCreate [<function register_ids_argument..add_ids_arguments at 0x7f13637f8bf0>, <function register_cache_arguments..add_cache_arguments at 0x7f1363811170>, <function register_upcoming_breaking_change_info..update_breaking_change_info at 0x7f1363811220>]
cli.azure.cli.core.azclierror: Traceback (most recent call last):
File "/usr/lib/python3.14/argparse.py", line 1744, in _check_help
formatter._expand_help(action)
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 672, in _expand_help
return help_string % params
~~~~~~~~~~~~^~~~~~~~
ValueError: unsupported format character 'Y' (0x59) at index 77

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/opt/azure-cli/lib/python3.14/site-packages/knack/cli.py", line 233, in invoke
cmd_result = self.invocation.execute(args)
File "/opt/azure-cli/lib/python3.14/site-packages/azure/cli/core/commands/init.py", line 570, in execute
self.parser.load_command_table(self.commands_loader)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
File "/opt/azure-cli/lib/python3.14/site-packages/azure/cli/core/parser.py", line 129, in load_command_table
param = AzCliCommandParser._add_argument(command_parser, arg)
File "/opt/azure-cli/lib/python3.14/site-packages/knack/parser.py", line 64, in _add_argument
return obj.add_argument(*scrubbed_options_list, **argparse_options)
~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 1558, in add_argument
self._check_help(action)
~~~~~~~~~~~~~~~~^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 1746, in _check_help
raise ValueError('badly formed help string') from exc
ValueError: badly formed help string

cli.azure.cli.core.azclierror: The command failed with an unexpected error. Here is the traceback:
az_command_data_logger: The command failed with an unexpected error. Here is the traceback:
cli.azure.cli.core.azclierror: badly formed help string
Traceback (most recent call last):
File "/usr/lib/python3.14/argparse.py", line 1744, in _check_help
formatter._expand_help(action)
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 672, in _expand_help
return help_string % params
~~~~~~~~~~~~^~~~~~~~
ValueError: unsupported format character 'Y' (0x59) at index 77

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/opt/azure-cli/lib/python3.14/site-packages/knack/cli.py", line 233, in invoke
cmd_result = self.invocation.execute(args)
File "/opt/azure-cli/lib/python3.14/site-packages/azure/cli/core/commands/init.py", line 570, in execute
self.parser.load_command_table(self.commands_loader)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
File "/opt/azure-cli/lib/python3.14/site-packages/azure/cli/core/parser.py", line 129, in load_command_table
param = AzCliCommandParser._add_argument(command_parser, arg)
File "/opt/azure-cli/lib/python3.14/site-packages/knack/parser.py", line 64, in _add_argument
return obj.add_argument(*scrubbed_options_list, **argparse_options)
~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 1558, in add_argument
self._check_help(action)
~~~~~~~~~~~~~~~~^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 1746, in _check_help
raise ValueError('badly formed help string') from exc
ValueError: badly formed help string
az_command_data_logger: badly formed help string
Traceback (most recent call last):
File "/usr/lib/python3.14/argparse.py", line 1744, in _check_help
formatter._expand_help(action)
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 672, in _expand_help
return help_string % params
~~~~~~~~~~~~^~~~~~~~
ValueError: unsupported format character 'Y' (0x59) at index 77

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "/opt/azure-cli/lib/python3.14/site-packages/knack/cli.py", line 233, in invoke
cmd_result = self.invocation.execute(args)
File "/opt/azure-cli/lib/python3.14/site-packages/azure/cli/core/commands/init.py", line 570, in execute
self.parser.load_command_table(self.commands_loader)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^
File "/opt/azure-cli/lib/python3.14/site-packages/azure/cli/core/parser.py", line 129, in load_command_table
param = AzCliCommandParser._add_argument(command_parser, arg)
File "/opt/azure-cli/lib/python3.14/site-packages/knack/parser.py", line 64, in _add_argument
return obj.add_argument(*scrubbed_options_list, **argparse_options)
~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 1558, in add_argument
self._check_help(action)
~~~~~~~~~~~~~~~~^^^^^^^^
File "/usr/lib/python3.14/argparse.py", line 1746, in _check_help
raise ValueError('badly formed help string') from exc
ValueError: badly formed help string
To check existing issues, please visit: https://github.com/Azure/azure-cli/issues
cli.knack.cli: Event: Cli.PostExecute [<function AzCliLogging.deinit_cmd_metadata_logging at 0x7f13639a8250>]
az_command_data_logger: exit code: 1
cli.main: Command ran in 0.545 seconds (init: 0.252, invoke: 0.294)
telemetry.main: Begin splitting cli events and extra events, total events: 1
telemetry.client: Accumulated 0 events. Flush the clients.
telemetry.main: Finish splitting cli events and extra events, cli events: 1
telemetry.save: Save telemetry record of length 8019 in cache file under /home/azgabur/.azure/telemetry/20260223161918162
telemetry.main: Begin creating telemetry upload process.
telemetry.process: Creating upload process: "/opt/azure-cli/bin/python /opt/azure-cli/lib/python3.14/site-packages/azure/cli/telemetry/init.py /home/azgabur/.azure /home/azgabur/.azure/telemetry/20260223161918162"
telemetry.process: Return from creating process 299144
telemetry.main: Finish creating telemetry upload process.

Expected behavior

To not crash

Environment Summary

{
"azure-cli": "2.83.0",
"azure-cli-core": "2.83.0",
"azure-cli-telemetry": "1.1.0",
"extensions": {}
}

Python 3.14.3

DISTRIB_ID="Arch"
DISTRIB_RELEASE="rolling"
DISTRIB_DESCRIPTION="Arch Linux"

Additional context

I tried installing azure-cli via system package manager and pipx, both resulting in same errors.

[yonzhan]

Thank you for opening this issue, we will look into it.

[jiasli]

TL;DR

This issue is caused by Python 3.14's change on argparse: python/cpython#124899. Azure CLI currently doesn't support Python 3.14 yet. Please use Python 3.13 instead.

---

When the error

  File "/usr/lib/python3.14/argparse.py", line 672, in _expand_help
    return help_string % params
           ~~~~~~~~~~~~^~~~~~~~
ValueError: unsupported format character 'Y' (0x59) at index 77

happens, the help_string in return help_string % params statement contains 'Display name of the service principal. If not present, default to azure-cli-%Y-%m-%d-%H-%M-%S where the suffix is the time of creation.'.

It comes from

azure-cli/src/azure-cli/azure/cli/command_modules/role/_params.py

Lines 187 to 189 in 1565a55

	c.argument('display_name', options_list=['--display-name', '--name', '-n'],
	help='Display name of the service principal. If not present, default to azure-cli-%Y-%m-%d-%H-%M-%S '
	'where the suffix is the time of creation.')

The help message doesn't follow the rule at https://docs.python.org/3/library/argparse.html#help

As the help string supports %-formatting, if you want a literal % to appear in the help string, you must escape it as %%.

Python 3.14's argparse now checks the help message and fails.

[jiasli]

The current Azure CLI dev branch cannot be install on Python 3.14 at all. @azgabur, How did you get dependencies installed?

Anyway, I am able to reproduce this error after bumping dependencies for Python 3.14 (#32859) and installing Azure CLI in Python 3.14.