Bug #21522: Accessing outer locals via eval in a Ractor returns false

• Status: Closed
• Assignee: ractor
• Target version: -
• ruby -v: ruby 3.5.0dev (2025-07-28T22:17:45Z master f1acf47ca2) +PRISM [arm64-darwin24]
• Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN

[tenderlovemaking (Aaron Patterson)]

Normally, if you try to access a local that's been defined outside the scope of the Ractor block, it'll raise an ArgumentError. However, if you try to access the local via eval it will return the value false.

foo = Object.new

begin
  Ractor.new {
    p foo
  }.value
rescue ArgumentError
end

Ractor.new {
  p eval("foo") # => false
}.value

I'm not sure how we fix this, since my guess is that we zero the environment when copying, but I wanted to file the issue so we can track it.

[andremuta (Andre Muta)]

Hi, I submitted a PR to fix this: https://github.com/ruby/ruby/pull/14940

[andremuta (Andre Muta)]

• Status changed from Open to Closed

Applied in changeset git|244a37bd53fb5c7ba219ef958b6adaa2c4b0b67e.

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Fixes [Bug #21522] eval isolation in Ractors for Prism