E4120#
Compiler diagnostic name: unhandled_error.
An infix operator application may raise an error, but the error is not handled.
Most error-producing function calls are checked directly at the call site. This diagnostic is used for operator applications after the operator has been resolved to a function whose effect may raise. The operation must either handle the error locally or appear in a context that can propagate it.
This diagnostic is currently tied to an operator-resolution path and is not monitored by a source-level error-code example.
Suggestion#
Handle the error with try/catch, or use the operator only inside a function
whose signature permits the raised error.