PharoCorePackageDependenciesTests make tests with packages not presents in pharo 1.2

Several tests from PharoCorePackageDependenciesTests raise errors  because it specify packages not present in pharo 1.2:

 'AST-Tests-Core' 
 'AST-Core'
 'AST-Semantic'

The error come from:

  referencesInPackageNamed: pkgNameAsString
        	| pi |
	         pi := PackageOrganizer default
				packageNamed: pkgNameAsString
				ifAbsent: [^ self].
                  ....
The package is not found, therefore it returns 'self', later in the code we iterate on that 'self', it raise a DNU Message. Maybe rather that returning self, we should return a more explicit error so that we know directly where does the problem comes from?
Anyway, I guess the main problem here is that the packages specified are not present in the image?

I opened an issue:http://code.google.com/p/pharo/issues/detail?id=3033