Andrej Mitrovic has found this D2 code produces errors:

import std.path : join;
enum rootdir = r"C:\Path\";
enum testdir = join(rootdir, "simple");
void main() {}



I have reduced that bug to:

int foo(int x, int y, int[] more...) {
    return 0;
}
enum r = foo(0, 0);
void main() {}


DMD 2.051 prints:
test.d(4): Error: variable __arrayArg1 is used before initialization
test.d(4): Error: cannot evaluate foo(0,0,(int[0u] __arrayArg1 = void;

 , cast(int[])__arrayArg1)) at compile time
test.d(4): Error: cannot evaluate foo(0,0,(int[0u] __arrayArg1 = void;

 , cast(int[])__arrayArg1)) at compile time