One type of locales I know are the LC_ env vars. So there the "ENV is a copy" applies too.
Another would be to read and write into locale files, such as JSON. But then the ame applies as with any database or IO: this is inherently race-condition-prone and that is by design.
Maybe grandparent is thinking about locales in many web frameworks, that is some global var which should not be shared across users. So that if you set `Locale.current = "EN_GB"` that applies for any (email)notifications, errors, files, responses or such, being sent out during that request/response and during any jobs that request/response may spawn. In e.g. Rails this "somewhat global var" is a Frankenstein, but works suprisingly stable, actually.
Another would be to read and write into locale files, such as JSON. But then the ame applies as with any database or IO: this is inherently race-condition-prone and that is by design.
Maybe grandparent is thinking about locales in many web frameworks, that is some global var which should not be shared across users. So that if you set `Locale.current = "EN_GB"` that applies for any (email)notifications, errors, files, responses or such, being sent out during that request/response and during any jobs that request/response may spawn. In e.g. Rails this "somewhat global var" is a Frankenstein, but works suprisingly stable, actually.