-fonly causes GDC to crash

[Jarrett Billingsley]

In an attempt to get MiniD to compile under the new GDC 0.20, I found out 
about the -fonly flag from DSSS.  It's what DSSS uses to "resolve circular 
dependencies."

Here's the thing -- I have no idea what this flag does.  I can't find 
documentation for it anywhere.  I did "gdc -v --help" and -fonly doesn't 
appear anywhere in the output.

This is the only way I have ever heard of anyone successfully compiling 
MiniD using GDC short of combining the two files which mutually import one 
another.

All I can get it to do is to give me an error.  Even in the simplest 
possible case:

gdc -fonly=test.d

I get the error:

Assertion failed: an_output_module, file 
../../gcc-3.4.2-20040916-1/gcc/d/d-lang
.cc, line 907

This application has requested the Runtime to terminate it in an unusual 
way.
Please contact the application's support team for more information.
dtest.d:0: internal compiler error: Aborted
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://www.mingw.org/bugs.shtml> for instructions.

Did this appear in 0.20?  Am I using it wrong?