[ruby-core:115918] [Ruby master Bug#20092] Warnings for anonymous parameters do not display in Ruby 3.4dev

27 Dec 2023

      Issue #20092 has been reported by koic (Koichi ITO).

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Bug #20092: Warnings for anonymous parameters do not display in Ruby 3.4dev
https://bugs.ruby-lang.org/issues/20092

* Author: koic (Koichi ITO)
* Status: Open
* Priority: Normal
* ruby -v: ruby 3.4.0dev (2023-12-26T22:32:38Z master be92bf4ff4) [x86_64-darwin22]
* Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN
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I encountered no expected warnings in Ruby 3.4dev.

## Reproduction code

```ruby
def anonymous(*, **, &)
  rest_block do
    foo(*)
  end

  kwrest_block do
    bar(**)
  end

  block_block do
    baz(&)
  end
end
```

## Expected Behavior (Ruby 3.3.0)

Warnings are displayed:

```ruby
$ ruby -vc example.rb
ruby 3.3.0 (2023-12-25 revision 5124f9ac75) [x86_64-darwin22]
example.rb: example.rb:3: anonymous rest parameter is also used within block (SyntaxError)
example.rb:7: anonymous keyword rest parameter is also used within block
example.rb:11: anonymous block parameter is also used within block
```

## Actual Behavior (Ruby 3.4dev)

No warning displayed:

```ruby
$ ruby -vc example.rb
ruby 3.4.0dev (2023-12-26T22:32:38Z master be92bf4ff4) [x86_64-darwin22]
Syntax OK
```

-- 
https://bugs.ruby-lang.org/