Hartley McGuire

It looks like this covers some of the same content as #50744. Let me get that merged first and then we can rebase this one

> And I'm even a bit more confused because https://guides.rubyonrails.org/v6.0/configuring.html#config-active-storage-replace-on-assign-to-many doesn't exist. The direct linking unfortunately wasn't added until later, but the configuration is second to last in the [Active...

UJS is dead #50535, so those files should not be changed

I'm not sure this is the correct solution. The issue is the `ConnectionPool` gets `discard!`ed on `fork` here: https://github.com/rails/rails/blob/e58d59ce489f7b7c48c0ace1b9d2ac03cb458258/activerecord/lib/active_record/connection_adapters/pool_config.rb#L82 and based on this comment https://github.com/rails/rails/blob/e58d59ce489f7b7c48c0ace1b9d2ac03cb458258/activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb#L284-L286 you really shouldn't be calling...

If I understand correctly, a new release of `turbo-rails` would resolve this right? I'm not sure there's anything to change here for Rails itself

This should be fixed in `turbo-rails` `2.0.6`

> I'm seeing the same issue in a fiber-based environment where multiple fibers can reuse the same connection I don't think an individual connection should ever be shared across threads...