Issue #18129 has been updated by dazuma (Daniel Azuma).
I've tried a number of different variations on this, but never got it to reproduce
(tried `ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-darwin22]` and `ruby 3.0.6p216
(2023-03-30 revision 23a532679b) [x86_64-darwin22]` since the original report did not
specify the Ruby version/build). I suggest we close, unless the original reporter has
additional information.
----------------------------------------
Bug #18129: Ractor-incompatible global variables can be accessed through alias
https://bugs.ruby-lang.org/issues/18129#change-105317
* Author: rm155 (Rohit Menon)
* Status: Open
* Priority: Normal
* Backport: 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN
----------------------------------------
Some global variables are not allowed in non-main Ractors. For example, the following code
does not run:
``` ruby
Ractor.new do
$/
end.take
#=> can not access global variables $/ from non-main Ractors (Ractor::IsolationError)
```
This error message is expected because $/ is not allowed outside the main Ractor.
However, if the variable is aliased, it sometimes bypasses this. For example, the
following code sometimes runs unexpectedly without error:
``` ruby
alias $alias_global_variable $/
Ractor.new do
$alias_global_variable
end.take
```
Sometimes, it correctly fails with the message “can not access global variables
$alias_global_variable from non-main Ractors (Ractor::IsolationError)”. However, because
the global variable is sometimes accessed without error, this could lead to data races.
--
https://bugs.ruby-lang.org/