Marcel Taeumel uploaded a new version of System to project The Trunk:
http://source.squeak.org/trunk/System-mt.829.mcz

==================== Summary ====================

Name: System-mt.829
Author: mt
Time: 13 May 2016, 1:54:56.020794 pm
UUID: 0d199e8c-ffd6-c449-a1a3-80716e8d2752
Ancestors: System-mt.828

Use only one implementation to remove all but one project from the system.

=============== Diff against System-mt.828 ===============

Item was changed:
  ----- Method: Project class>>removeAllButCurrent (in category 'utilities') -----
  removeAllButCurrent
  	"Project removeAllButCurrent"
  
+ 	self current removeAllOtherProjects.!
- 	AllProjects := nil.
- 	Smalltalk garbageCollect.
- 
- 	self removeAll: (Project allSubInstances copyWithout: Project current).
- 
- 	AllProjects := nil.
- 	Smalltalk garbageCollect.
- 
- 	Smalltalk garbageCollect.
- 	Project rebuildAllProjects.
- 	^AllProjects!