scrapy parse -h throws error

[alexpdev]

Description

running scrapy parse -h from inside of a project throws an error.

Steps to Reproduce

1. scrapy startproject example
2. cd example
3. scrapy parse -h

Expected behavior: It should show the help message output for the parse command
Actual behavior: Throws error and displays traceback information
Reproduces how often: Every time I tried it.

Versions

v2.6.1

Additional context

I identified the issue and will submit a PR shortly.

[elacuesta]

I can reproduce. For completeness, here's the full output I'm getting:

$ scrapy parse -h
Traceback (most recent call last):
  File "/home/eugenio/zyte/scrapy/venv-scrapy/bin/scrapy", line 33, in <module>
    sys.exit(load_entry_point('Scrapy', 'console_scripts', 'scrapy')())
  File "/home/eugenio/zyte/scrapy/scrapy/cmdline.py", line 141, in execute
    opts, args = parser.parse_known_args(args=argv[1:])
  File "/usr/local/lib/python3.9/argparse.py", line 1851, in parse_known_args
    namespace, args = self._parse_known_args(args, namespace)
  File "/usr/local/lib/python3.9/argparse.py", line 2060, in _parse_known_args
    start_index = consume_optional(start_index)
  File "/usr/local/lib/python3.9/argparse.py", line 2000, in consume_optional
    take_action(action, args, option_string)
  File "/usr/local/lib/python3.9/argparse.py", line 1928, in take_action
    action(self, namespace, argument_values, option_string)
  File "/usr/local/lib/python3.9/argparse.py", line 1092, in __call__
    parser.print_help()
  File "/usr/local/lib/python3.9/argparse.py", line 2548, in print_help
    self._print_message(self.format_help(), file)
  File "/usr/local/lib/python3.9/argparse.py", line 2532, in format_help
    return formatter.format_help()
  File "/usr/local/lib/python3.9/argparse.py", line 283, in format_help
    help = self._root_section.format_help()
  File "/usr/local/lib/python3.9/argparse.py", line 214, in format_help
    item_help = join([func(*args) for func, args in self.items])
  File "/usr/local/lib/python3.9/argparse.py", line 214, in <listcomp>
    item_help = join([func(*args) for func, args in self.items])
  File "/usr/local/lib/python3.9/argparse.py", line 214, in format_help
    item_help = join([func(*args) for func, args in self.items])
  File "/usr/local/lib/python3.9/argparse.py", line 214, in <listcomp>
    item_help = join([func(*args) for func, args in self.items])
  File "/usr/local/lib/python3.9/argparse.py", line 530, in _format_action
    help_text = self._expand_help(action)
  File "/usr/local/lib/python3.9/argparse.py", line 626, in _expand_help
    return self._get_help_string(action) % params
TypeError: %d format: a number is required, not dict

I suspect this was valid with optparse and broke on the move to argparse (#5374)

[Urahara]

@wRAR @Gallaecio Can we close this issue since is fixed on 2.6?

[wRAR]

It's not fixed in master and I'm not sure what is our policy for this.

[alexpdev]

Hello, should I close this issue?

[Gallaecio]

Not yet. We will close it once we port the change from the 2.6 branch to the main branch.

[Gallaecio]

Actually, since we merge 2.6.2 into the main branch as part of the release process, there is no reason to keep this open.