[ruby-core:121093] [Ruby master Bug#21146] VM_ASSERT(expr) gives bad bug report results when another ractor fails an assertion during printing of report

17 Feb 2025


      Issue #21146 has been reported by luke-gru (Luke Gruber).

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Bug #21146: VM_ASSERT(expr) gives bad bug report results when another ractor fails an assertion during printing of report
https://bugs.ruby-lang.org/issues/21146

* Author: luke-gru (Luke Gruber)
* Status: Open
* Backport: 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN
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test.rb:
```ruby
rs = 100.times.map do
  Ractor.new do
    cnt = rand 3
    cnt += 1 if cnt.zero?
    sleep cnt
    100.times do |i|
      if i != 0 && i % 50 == 0
        Ractor.fail_assert
      end
    end
  end
end
```

ractor.rb:

```ruby
def self.fail_assert
  __builtin_cexpr! %q{
    VM_ASSERT(0), Qfalse
  }
end
```
...
make run
I would like to be able to see the bug report for the first failed assertion, without any output from the other ractors.


-- 
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