30029 ----- 10173 ClassBuilder cannot safely modify a class why using it https://pharo.fogbugz.com/f/cases/10173/ 10130 isNil and ... notNil https://pharo.fogbugz.com/f/cases/10130 10248 Remove old Pharo20 repository in Pharo30 https://pharo.fogbugz.com/f/cases/10248 Diff information: http://smalltalkhub.com/#!/~Pharo/Pharo30/diff/Kernel-MarcusDenker.1356