Erreur Core library

Quand je compile mon projet android avec Eclipse, j'ai l'erreur suivante :

[2009-06-05 16:08:34 - Android]
Attempt to include a core VM class in something other than a core library.
It is likely that you have attempted to include the core library from a desktop
virtual machine into an application, which will most assuredly not work. If
you really intend to build a core library -- which is only appropriate as
part of creating a full virtual machine binary, as opposed to compiling an
application -- then use the "--core-library" option to suppress this error
message. If you go ahead and use "--core-library" but are in fact building
an application, then please be aware that your build will still fail at some
point; you will simply be denied the pleasure of reading this helpful error
message.
[2009-06-05 16:08:34 - Android] 1 error; aborting

Mais impossible de trouver ou je dois passer l'option "--core-library" dans Eclipse. Quelqu'un a deja eu ce problème ?