immutable and std.parallelism.Task

[Andrew Wiley]

I'm pretty sure this is a bug, but the error makes me think I'm somehow
using immutable incorrectly:

import std.parallelism;

class Test {
}

void doSomething(immutable(Test) test) {
}

void main() {
        immutable(Test) test = new immutable(Test)();
        taskPool().put(task!(doSomething)(test));
}


compiler output:
Error: can only initialize const member __args_field_0 inside constructor
Error: this is not mutable
/usr/include/d2/4.6.0/std/parallelism.d:734: Error: template instance
std.parallelism.Task!(doSomething,immutable(Test)) error instantiating
tasktest.d:11:        instantiated from here:
task!(doSomething,immutable(Test))