May be tested on simple hello world:
---
import std.stdio;
int main() {
std.stdio.writefln("Hello World!");
std.stdio.readln;
return 0;
}
---
gdc test.d -o test
---
/usr/local/lib/gcc/i386-portbld-freebsd8.0/../../libgphobos.a(math.o)(.text+0xa45): In function `_D3std4math6tgammaFeZe':
../.././../gcc-4.1-20080428/libphobos/std/math.d:1136: undefined reference to `tgammal'
...
