x.p6

my $s1 = supply {
    whenever Promise.in(1) {
        die "oops";
    }
}
my $s2 = supply {
    whenever Supply.interval(0.5).head(5) {
        .emit;
    }
}

my $ex;
react {
    whenever $s1 {
        QUIT {
            default {
                say "caught";
                $ex //= $_;
            }
        }
    }
    whenever $s2 { .say }
}
$ex.?rethrow;