class X::Proc::Async::MustBeStarted is Exception {}

Several methods from Proc::Async expect that the external program has been spawned (by calling .start on it), including say, write, print and close-stdin. If one of those methods is called before .start was called, they throw an exception of type X::Proc::Async::MustBeStarted.'echo':w).say(42);
CATCH { default { put .^name''.Str } };
# OUTPUT: «X::Proc::Async::MustBeStarted: Process must be started first before calling 'say'␤»


method method§

method method(X::Proc::Async::MustBeStarted:D --> Str:D)

Returns the name of the method that was illegally called before starting the external program.