OPTLINK is missing files when I try to include debugging info into build

[Matt]

I was trying to check out windbg with a project I am working on. 
The program currently consists of two D files (main.d, 
Application.d) and three Derelict3 import libs (DerelictUtil, 
DerelictSDL2, DerelictGL3). Without debug info, the following 
console command runs fine;

---

dmd main.d Application.d DerelictUtil.lib DerelictSDL2.lib 
DerelictGL3.lib

---

However, no matter where I put either the -g or -gc switches, 
Optlink complains with 'Error 118: Filename Expected', and 
proceeds to spit out my PATH environment variable. I tried with 
just a 'Hello World' program that only imports 'std.stdio', and I 
get the same problem.

Could anyone explain to me what the problem is? I have the 
feeling that there is something I need to do to set up Optlink, 
however I installed from the Windows binary on dlang.org. If it 
matters, I'm running Win7