Hi,
I found the origin of the problem. Lazarus comes with the package ImagesForLazarus which is distributed for Mac compiled with stabs (-gs option). It is needed to open this package and change the debugger option to automatic (-g) option, then compile this package.
I have now problems with UTF8 functions not found while compiling GLScene, so the story is not over for me. However, I open a bug report for this now.
As I understand, the take home message is: if you get stabs error, look for units previously compiled with -gs option.
Ciao,
Gilles Marcou