Hi guys. We are doing some experiments with Fuel and GZip streams... Now I have a beatiful test like this: testMethodContextThisContext | materializedContext context | context := thisContext copy. materializedContext := self resultOfSerializeAndMaterialize: context. and it crashes like crazy. From the VM crash stack, I can see: Smalltalk stack dump: 0xbff66ba4 M GZipWriteStream(DeflateStream)>deflateBlock 447551436: a(n) GZipWriteStream 0xbff66bc8 M GZipWriteStream(DeflateStream)>nextPutAll: 447551436: a(n) GZipWriteStream 0xbff66be4 M GZipWriteStream(DeflateStream)>next:putAll:startingAt: 447551436: a(n) GZipWriteStream 0xbff66c08 M FLBufferedWriteStream>flushBuffer 448048664: a(n) FLBufferedWriteStream 0xbff66c20 M FLBufferedWriteStream>nextBytesPutAll: 448048664: a(n) FLBufferedWriteStream 0xbff66c40 M FLBufferedWriteStream>nextStringPut: 448048664: a(n) FLBufferedWriteStream 0xbff66c5c M FLByteStringCluster>serialize:on: 448054196: a(n) FLByteStringCluster 0xbff66c7c M FLByteStringCluster(FLPrimitiveCluster)>serializeInstance:with: 448054196: a(n) FLByteStringCluster 0xbff66ca0 M [] in FLByteStringCluster(FLIteratingCluster)>serializeInstances: 448054196: a(n) FLByteStringCluster 0xbff66cc8 M IdentitySet(Set)>do: 451711680: a(n) IdentitySet 0xbff66ce4 M FLByteStringCluster(FLIteratingCluster)>serializeInstances: 448054196: a(n) FLByteStringCluster 0xbff66d00 M FLByteStringCluster(FLIteratingCluster)>serializeInstancesStepWith: 448054196: a(n) FLByteStringCluster 0xbff66d1c M FLSerialization>clusterInstancesStepOf: 448053428: a(n) FLSerialization 0xbff66d38 M [] in FLSerialization>instancesStep 448053428: a(n) FLSerialization 0xbff66d58 M OrderedCollection>do: 449989736: a(n) OrderedCollection 0xbff66d74 M FLSerialization>instancesStep 448053428: a(n) FLSerialization 0xbff66d8c M FLSerialization>run 448053428: a(n) FLSerialization 0xbff66db0 I [] in FLSerializer>defaultSerialization 447550464: a(n) FLSerializer 0xbff66dd8 M [] in FLSerializer>serialize:on: 447550464: a(n) FLSerializer 0xbff66df8 M BlockClosure>ensure: 448052884: a(n) BlockClosure 0xbff66e18 M FLSerializer>serialize:on: 447550464: a(n) FLSerializer 0xbff66e3c M [] in FLMethodContextSerializationTest(FLSerializationTest)>serialize: 447235380: a(n) FLMethodContextSerializationTest 0xbff66e60 M [] in GZipWriteStream class(PositionableStream class)>on:do: 419845144: a(n) GZipWriteStream class 0xbff66e80 M BlockClosure>ensure: 448048616: a(n) BlockClosure 0xbff66ea0 M GZipWriteStream class(PositionableStream class)>on:do: 419845144: a(n) GZipWriteStream class 0xbff66ec4 M [] in FLGZipStrategy>writeStreamDo: 447550896: a(n) FLGZipStrategy 0xbff66ee0 M FLByteArrayStreamStrategy>writeStreamDo: 447550884: a(n) FLByteArrayStreamStrategy 0xbff66efc M FLGZipStrategy>writeStreamDo: 447550896: a(n) FLGZipStrategy 0xbff66f18 M FLMethodContextSerializationTest(FLSerializationTest)>serialize: 447235380: a(n) FLMethodContextSerializationTest 0xbff66f34 M FLMethodContextSerializationTest(FLSerializationTest)>resultOfSerializeAndMaterialize: 447235380: a(n) FLMethodContextSerializationTest 0xbff66f58 M FLMethodContextSerializationTest>testMethodContextThisContext 447235380: a(n) FLMethodContextSerializationTest any idea of where I should start to look at? Thanks -- Mariano http://marianopeck.wordpress.com