I built new Cog by taking latest VMMaker-oscog.46 on MacOS VM still crashing at some random point during running all pharo-core image tests. Once i were able to run w/o crash and found following failures: MethodContextTest debug: #testClosureRestart because actually this one: MethodContextTest new privRestartBlockArgsNoRemoteTempsTest i'm not sure if this is a compiler issue (maybe it shuffling the temps) or because of Cog, which doesn't likes restarts like that :) BecomeTest>>testBecomeIdentityHash. Sometimes passes, sometimes not (try doing following in workspace): | a b | a := 'ab' copy. b := 'cd' copy. self assert: (a identityHash ~= b identityHash). a become: b. self assert: (a ~= b). self assert: (a identityHash ~= b identityHash). i'm not sure if this is a big issue.. afaik, #become: don't gives any guarantees about copying identityhash. P.S. yesterday i were able to successfully build Cog on linux using cmake configs i generating. but it crashing at first #commonReturn point, which is really weird :) I tried multiple images, same result. The crash happens in given loop: while (closure != GIV(nilObj)) { home = longAt((closure + BaseHeaderSize) + (ClosureOuterContextIndex << ShiftForWord)); closure = longAt((home + BaseHeaderSize) + (ClosureIndex << ShiftForWord)); } -- Best regards, Igor Stasenko AKA sig.