Invalid help message inside interactive help utility

Documentation

From REPL, >>> help(help) produces valid output.

From inside interactive help utility, help> help(help), produces less useful output.

I suppose I would have expected something like, "cannot use help() inside of help(), use help instead".

Here is an example.

~$ python3
Python 3.10.4 (main, Apr  2 2022, 09:04:19) [GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> help(help)

>>> help() # works as expected

Welcome to Python 3.10's help utility!

If this is your first time using Python, you should definitely check out
the tutorial on the internet at https://docs.python.org/3.10/tutorial/.

Enter the name of any module, keyword, or topic to get help on writing
Python programs and using Python modules.  To quit this help utility and
return to the interpreter, just type "quit".

To get a list of available modules, keywords, symbols, or topics, type
"modules", "keywords", "symbols", or "topics".  Each module also comes
with a one-line summary of what it does; to list the modules whose name
or summary contain a given string such as "spam", type "modules spam".

help> help(help)
No Python documentation found for 'help(help)'.
Use help() to get the interactive help utility.
Use help(str) for help on the str class.

# typing just help works as expected
help> 
You are now leaving help and returning to the Python interpreter.
If you want to ask for help on a particular object directly from the
interpreter, you can type "help(object)".  Executing "help('string')"
has the same effect as typing a particular string at the help> prompt.
>>> 

Linked PRs

• gh-148863

help() エントリーポイントから対話型ヘルプユーティリティを開始し、>>> help(help) と比較しながら help> help(help) を再現します。ヘルププロンプトがドキュメントが見つからないと報告するのではなく、コンテキストを考慮した有用な診断を提供すれば完了です。この issue では、実行するファイルやテストは指定されていません。