Unittests being broken

[Ruby The Roobster]

Some code I have:

```d
alias Operator = dstring function(dstring input);

//List of all operations.
package Operator[dstring] opList;

//List of all functions.
package dstring[dstring] funcList;

//Functions that may not be deleted.
package dstring[dstring] noTouch;

//Initialize the basic arithmetic operations to null: these will 
be handled by operator overloading.
shared static this()
{
     opList["+"d] = null;
	opList["-"d] = null;
	opList["*"d] = null;
	opList["/"d] = null;
	opList["^^"d] = null;
}

//Add the neccessary functions to noTouch.
shared static this()
{
     noTouch["ln(x) = num(num)"d] = null;
     noTouch["sin(x) = num(num)"d] = null;
     noTouch["cos(x) = num(num)"d] = null;
     noTouch["tan(x) = num(num)"d] = null;
     noTouch["csc(x) = num(num)"d] = null;
     noTouch["sec(x) = num(num)"d] = null;
     noTouch["cot(x) = num(num)"d] = null;
     noTouch["Γ(x) = num(num)"d] = null;
     noTouch["δ(x) = num(num)"d] = null;
     assert("δ(x) = num(num)"d in noTouch);
}

//CUT

//CUT END

bool removeFunction(dstring funcdef) @safe @nogc nothrow
{
     if(funcdef !in funcList || funcdef in noTouch) //Make sure 
that the function acutally exists and isn't non-removable.
         return false;
     funcList.remove(funcdef);
     return true;
}

///
unittest
{
     dstring func = "x + 1"d;
     assert(!removeFunction("a(x) = num(num)"d));
     funcList["δ(x) = num(num)"d] = null;
     assert("δ(x) = num(num)"d in noTouch);
     assert(!removeFunction("δ(x) = num(num)"d));
     funcList.remove("δ(x) = num(num)");
     //registerFunction("a(x) = num(num)"d, func);
     //assert(removeFunction("a(x) = num(num)"d));
}
```

Running dub test (with silly) returns no errors.

Now, comment out the following line of code:

```d
assert("δ(x) = num(num)"d in noTouch);
```

Running dub test fails, with the removal of this line being the 
culprit.

However, this code (plus an added main function) passes when 
pasted into run.dlang.io.

I have tried building both with dmd 2.099.1 and ldc 1.029.0 on 
Windows 10 x86_64 with -m64, and it fails.

What can I do to fix this?