Registry.update_value/3 error when called from Task but not from iex

[al2o3cr]

Cross-linking a useful analogy from another thread:

Can I get some clarification on why Registry is written the way it is?

It is a key-value process storage. So you can think of it having three dimensions (key, value, pid), instead of two, and, it also allows duplicate keys with a single process. The process bit is crucial, it is not simply a key-value storage. If that’s your goal, :ets tables are most likely a better choice.