You see hernan doing positively is the best way to make that things happen We can have a preUnload hook Now we should check how it fits with cleanForProduction and others. But we should definitively have a way to express this. So let us see how we can design it and then just implement it. I'm sure that GT people are open to such hooks and if you really want to get a better Pharo for you then talk to them and us. https://pharo.fogbugz.com/f/cases/18997/Add-unload-to-package-manifest-in-QA https://pharo.fogbugz.com/f/cases/18998/Add-unload-to-package-manifest-of-Sp... https://pharo.fogbugz.com/f/cases/18999/Add-unload-to-package-manifest-in-GT... https://pharo.fogbugz.com/f/cases/19000/Add-unload-to-package-manifest-in-GT Stef