Hi guys in RPackage there is a method named withOrganizer:do: defined as follows and I would like to test it to understand really if it does what it says. withOrganizer: aNewOrganizer do: aBlock "Perform an action locally to aNewOrganizer. Does not impact any other organizers." | old shouldRegisterAtTheEnd| [ old := self organizer. shouldRegisterAtTheEnd := false. old hasRegistered ifTrue: [ old unregister. shouldRegisterAtTheEnd := true. ]. self organizer: aNewOrganizer. aBlock cull: aNewOrganizer.] ensure: [ self organizer: old. shouldRegisterAtTheEnd ifTrue: [ self organizer register. ]. aNewOrganizer unregister. ] So I wrote two tests testWithDoIsCorrectlyReinstallingDefault "self debug: #testWithDoIsCorrectlyReinstallingDefault" | current empty | current := RPackageOrganizer default. empty := RPackageOrganizer basicNew initialize. RPackage withOrganizer: empty do: [ self assert: (SystemAnnouncer announcer hasSubscriber: empty). self deny: (SystemAnnouncer announcer hasSubscriber: current)]. self assert: (SystemAnnouncer announcer hasSubscriber: current). self deny: (SystemAnnouncer announcer hasSubscriber: empty) and testWithDoIsCorrectlyReinstallingDefaultEvenIfHalt "self debug: #testWithDoIsCorrectlyReinstallingDefaultEvenIfHalt" | current empty | current := RPackageOrganizer default. empty := RPackageOrganizer basicNew initialize. RPackage withOrganizer: empty do: [ self error. self assert: (SystemAnnouncer announcer hasSubscriber: empty). self deny: (SystemAnnouncer announcer hasSubscriber: current)]. self assert: (SystemAnnouncer announcer hasSubscriber: current). self deny: (SystemAnnouncer announcer hasSubscriber: empty) Now I would like to make sure that I raise an error or whaever to make sure that the ensure: block argument is executed. Does anybody have an idea how I can do that. because self error does not work. Stef