[Lazarus] Linker error

[Hans-Peter Diettrich]

AFAIR there was already a thread about problems with the linker (debug 
info), now I also have problems, starting with
   DocGui.lpr(21,1) Error: Undefined symbol: DEBUGINFO_$UMAKESKEL
and summing up in 50 errors :-(

Here's some background information:

Win7 (64 bit), building default (32 bit) GUI application (DocGui).
Using FPC trunk, required to compile the latest FPDoc version.
Made a package from the fpc\utils\fpdoc units, that works fine for 
commandline programs.

Now I created a GUI program, that works fine as long as the package is 
added to the project but not really used. Trouble starts when I try to 
use a unit from that package :-(

What's the problem, and how to fix it?

DoDi