32-bit Linux Cog VM segfaults after a few seconds

[LinqLover]

I downloaded squeak.cog.spur_linux32x86 from the new release (202603271636) and installed the required 32-bit libraries (multiarch) on my Ubuntu 24.04 64-bit system. When I run the 32-bit VM with either Squeak6.0-22148-32bit.image or Squeak6.1alpha-23704-32bit.image (both freshly retrieved from files.squeak.org), it crashes after a few seconds:

Output

christoph@tuxedo-christoph:~/Downloads/squeak.cog.spur_linux32x86/sqcogspur32linuxht$ ./squeak ~/Downloads/Squeak6.1alpha-23704-32bit/Squeak6.1alpha-23704-32bit.image 
pthread_setschedparam failed: Operation not permitted
This VM uses a separate heartbeat thread to update its internal clock
and handle events.  For best operation, this thread should run at a
higher priority, however the VM was unable to change the priority.  The
effect is that heavily loaded systems may experience some latency
issues.  If this occurs, please create the appropriate configuration
file in /etc/security/limits.d/ as shown below:
cat <<END | sudo tee /etc/security/limits.d/squeak.conf


 hard    rtprio  2



 soft    rtprio  2



END
and report to the squeak mailing list whether this improves behaviour.
You will need to log out and log back in for the limits to take effect.

For more information please see

https://github.com/OpenSmalltalk/opensmalltalk-vm/releases/tag/r3732#linux

Aborted (core dumped)
christoph@tuxedo-christoph:~/Downloads/squeak.cog.spur_linux32x86/sqcogspur32linuxht$ ./squeak ~/Downloads/Squeak6.0-22148-32bit/Squeak6.0-22148-32bit.image

pthread_setschedparam failed: Operation not permitted

This VM uses a separate heartbeat thread to update its internal clock

and handle events.  For best operation, this thread should run at a

higher priority, however the VM was unable to change the priority.  The

effect is that heavily loaded systems may experience some latency

issues.  If this occurs, please create the appropriate configuration

file in /etc/security/limits.d/ as shown below:
cat <<END | sudo tee /etc/security/limits.d/squeak.conf


 hard    rtprio  2



 soft    rtprio  2



END
and report to the squeak mailing list whether this improves behaviour.
You will need to log out and log back in for the limits to take effect.

For more information please see

https://github.com/OpenSmalltalk/opensmalltalk-vm/releases/tag/r3732#linux

stack page bytes 8192 available headroom 6888 minimum unused headroom 7048
Segmentation fault Tue Apr 21 19:53:20 2026
/home/christoph/Downloads/squeak.cog.spur_linux32x86/sqcogspur32linuxht/lib/squeak/7.0-202603271636-32bit/squeak

Squeak VM version: 7.0-202603271636  Sun Mar 29 14:07:49 UTC 2026 gcc 11 [Production Spur i686 VM]

Built from: CoInterpreter VMMaker.oscog-eem.3738 uuid: c3a9466e-a7e5-46c2-92fa-cdd228ffecef Mar 29 2026

With: StackToRegisterMappingCogit VMMaker.oscog-eem.3724 uuid: 4f19a1df-89b9-4dc2-9096-99d4c29a72b7 Mar 29 2026

Revision: VM: 202603271636 https://github.com/OpenSmalltalk/opensmalltalk-vm

Date: Fri Mar 27 17:36:22 2026 CommitHash: a8ed1b5

Plugins: 202603271636 https://github.com/OpenSmalltalk/opensmalltalk-vm

Build host: Linux runnervm19da2 6.8.0-1044-azure #50~22.04.1-Ubuntu SMP Wed Dec  3 15:13:22 UTC 2025 i686 athlon i686 GNU/Linux

plugin path: ./lib/squeak/7.0-202603271636-32bit [default: /home/christoph/Downloads/squeak.cog.spur_linux32x86/sqcogspur32linuxht/lib/squeak/7.0-202603271636-32bit/]
C stack backtrace & registers:

eax 0x59d9a8ef ebx 0x56812c78 ecx 0x00000000 edx 0x000e0c5d

edi 0x00000001 esi 0x00000001 ebp 0x00000088 esp 0xffc5a828

eip 0x566a6ba8

*./lib/squeak/7.0-202603271636-32bit/squeak(+0x27ba8)[0x566a6ba8]

./lib/squeak/7.0-202603271636-32bit/squeak(+0xa3eb7)[0x56722eb7]

./lib/squeak/7.0-202603271636-32bit/squeak(+0xa4282)[0x56723282]

linux-gate.so.1(__kernel_rt_sigreturn+0x0)[0xf07355a0]

./lib/squeak/7.0-202603271636-32bit/squeak(+0x27ba8)[0x566a6ba8]

./lib/squeak/7.0-202603271636-32bit/squeak(+0x55355)[0x566d4355]

./lib/squeak/7.0-202603271636-32bit/squeak(+0x559ed)[0x566d49ed]

./lib/squeak/7.0-202603271636-32bit/squeak(+0x55ae6)[0x566d4ae6]

[0x580f05a8]

[0x5812201e]

[0x5812aff1]

[0x5812ae0e]

[0x5812ad8e]

[0x58135303]

[0x5812d4c5]

[0x580f0fe8]

[0xffc59adc]
Smalltalk stack dump:

0xffc78800 I IndentingListItemMorph>drawOn: 0x582ce6a0: a(n) IndentingListItemMorph

0xffc7881c M FormCanvas(Canvas)>draw: 0x5847f4e8: a(n) FormCanvas

0xffc78838 M FormCanvas(Canvas)>drawMorph: 0x5847f4e8: a(n) FormCanvas

0xffc78854 M IndentingListItemMorph(Morph)>fullDrawOn: 0x582ce6a0: a(n) IndentingListItemMorph

0xffc78870 M FormCanvas(Canvas)>fullDraw: 0x5847f4e8: a(n) FormCanvas

0xffc7888c M FormCanvas(Canvas)>fullDrawMorph: 0x5847f4e8: a(n) FormCanvas

0xffc788ac M [] in TransformMorph>drawSubmorphsOn: 0x582c5650: a(n) TransformMorph

0xffc788cc M Array(SequenceableCollection)>reverseDo: 0x582ccad0: a(n) Array

0xffc7668c M [] in TransformMorph>drawSubmorphsOn: 0x582c5650: a(n) TransformMorph

0xffc766a8 M FormCanvas(Canvas)>translateBy:clippingTo:during: 0x58469ef8: a(n) FormCanvas

0xffc766e8 M FormCanvas>transformBy:clippingTo:during:smoothing: 0x58469ef8: a(n) FormCanvas

0xffc76710 M TransformMorph>drawSubmorphsOn: 0x582c5650: a(n) TransformMorph

0xffc7672c M TransformMorph(Morph)>fullDrawOn: 0x582c5650: a(n) TransformMorph

0xffc76748 M FormCanvas(Canvas)>fullDraw: 0x58469ef8: a(n) FormCanvas

0xffc76764 M FormCanvas(Canvas)>fullDrawMorph: 0x58469ef8: a(n) FormCanvas

0xffc76784 M [] in PluggableTreeMorph(Morph)>drawSubmorphsOn: 0x582c1cd0: a(n) PluggableTreeMorph

0xffc767a4 M Array(SequenceableCollection)>reverseDo: 0x582c5548: a(n) Array

0xffc767c0 M [] in PluggableTreeMorph(Morph)>drawSubmorphsOn: 0x582c1cd0: a(n) PluggableTreeMorph

0xffc767e0 M PluggableTreeMorph(Morph)>drawSubmorphsOn: 0x582c1cd0: a(n) PluggableTreeMorph

0xffc767fc M PluggableTreeMorph(Morph)>fullDrawOn: 0x582c1cd0: a(n) PluggableTreeMorph

0xffc76818 M FormCanvas(Canvas)>fullDraw: 0x58469ef8: a(n) FormCanvas

0xffc76834 M FormCanvas(Canvas)>fullDrawMorph: 0x58469ef8: a(n) FormCanvas

0xffc76854 M [] in PluggableSystemWindow(Morph)>drawSubmorphsOn: 0x582bd950: a(n) PluggableSystemWindow

0xffc76874 M Array(SequenceableCollection)>reverseDo: 0x583b5fd0: a(n) Array

0xffc76890 M [] in PluggableSystemWindow(Morph)>drawSubmorphsOn: 0x582bd950: a(n) PluggableSystemWindow

0xffc768b0 M PluggableSystemWindow(Morph)>drawSubmorphsOn: 0x582bd950: a(n) PluggableSystemWindow

0xffc768cc M PluggableSystemWindow(Morph)>fullDrawOn: 0x582bd950: a(n) PluggableSystemWindow

0xffc7468c M FormCanvas(Canvas)>fullDraw: 0x58469ef8: a(n) FormCanvas

0xffc746a8 M FormCanvas(Canvas)>fullDrawMorph: 0x58469ef8: a(n) FormCanvas

0xffc746f8 M [] in WorldState>drawWorld:submorphs:invalidAreasOn: 0x58d9bf80: a(n) WorldState

0xffc74728 M Rectangle>allAreasOutsideList:startingAt:do: 0x582c49e8: a(n) Rectangle

0xffc7474c M Rectangle>allAreasOutsideList:do: 0x582c49e8: a(n) Rectangle

0xffc74788 M [] in WorldState>drawWorld:submorphs:invalidAreasOn: 0x58d9bf80: a(n) WorldState

0xffc747ac M Array(SequenceableCollection)>do: 0x58469698: a(n) Array

0xffc747dc M WorldState>drawWorld:submorphs:invalidAreasOn: 0x58d9bf80: a(n) WorldState

0xffc74814 M WorldState>displayWorld:submorphs: 0x58d9bf80: a(n) WorldState

0xffc74834 M PasteUpMorph>privateOuterDisplayWorld 0x58da3cb8: a(n) PasteUpMorph

0xffc7484c M PasteUpMorph>displayWorld 0x58da3cb8: a(n) PasteUpMorph

0xffc7486c M [] in WorldState>displayWorldSafely: 0x58d9bf80: a(n) WorldState

0xffc7488c M FullBlockClosure(BlockClosure)>on:do: 0x58466810: a(n) FullBlockClosure

0xffc748b0 M WorldState>displayWorldSafely: 0x58d9bf80: a(n) WorldState

0xffc748d0 M [] in WorldState>doOneCycleNowFor: 0x58d9bf80: a(n) WorldState

0xffc5e5c0 M [] in ActiveWorldVariable class(DynamicVariable class)>value:during: 0x58d8f788: a(n) ActiveWorldVariable

0xffc5e5e0 M FullBlockClosure(BlockClosure)>ensure: 0x58464920: a(n) FullBlockClosure

0xffc5e608 M ActiveWorldVariable class(DynamicVariable class)>value:during: 0x58d8f788: a(n) ActiveWorldVariable

0xffc5e630 M [] in ActiveWorldVariable class>value:during: 0x58d8f788: a(n) ActiveWorldVariable

0xffc5e650 M FullBlockClosure(BlockClosure)>ensure: 0x58464850: a(n) FullBlockClosure

0xffc5e670 M ActiveWorldVariable class>value:during: 0x58d8f788: a(n) ActiveWorldVariable

0xffc5e690 M PasteUpMorph>becomeActiveDuring: 0x58da3cb8: a(n) PasteUpMorph

0xffc5e6b8 I WorldState>doOneCycleNowFor: 0x58d9bf80: a(n) WorldState

0xffc5e6dc I WorldState>doOneCycleFor: 0x58d9bf80: a(n) WorldState

0xffc5e700 I PasteUpMorph>doOneCycle 0x58da3cb8: a(n) PasteUpMorph

0xffc5e720 I PreferenceWizardMorph>refreshWorld 0x583b6a78: a(n) PreferenceWizardMorph

0xffc5e740 I PreferenceWizardMorph>showWelcome 0x583b6a78: a(n) PreferenceWizardMorph

0xffc5e760 I PreferenceWizardMorph>openInWorld 0x583b6a78: a(n) PreferenceWizardMorph

0xffc5e780 I PreferenceWizardMorph class>open 0x58e4e2b0: a(n) PreferenceWizardMorph

0xffc5e7a4 I [] in ReleaseBuilder class>prepareEnvironment 0x58994140: a(n) ReleaseBuilder

0xffc5e7c8 I ReleaseBuilder class>startUp: 0x58994140: a(n) ReleaseBuilder

0xffc5e7f4 M [] in SmalltalkImage>send:toClassesNamedIn:with: 0x589aa238: a(n) SmalltalkImage

0xffc5e81c I OrderedCollection>do: 0x58a4b4b0: a(n) OrderedCollection

0xffc5e844 I SmalltalkImage>send:toClassesNamedIn:with: 0x589aa238: a(n) SmalltalkImage

0xffc5e870 I SmalltalkImage>processStartUpList: 0x589aa238: a(n) SmalltalkImage

0xffc5e894 I SmalltalkImage>startUpPostSnapshot: 0x589aa238: a(n) SmalltalkImage

0xffc5e8c0 I SmalltalkImage>snapshot:andQuit:withExitCode:embedded: 0x589aa238: a(n) SmalltalkImage

0x5ad3ee30 s SmalltalkImage>snapshot:andQuit:embedded: 0x589aa238: a(n) SmalltalkImage

0x5ad3eff0 s SmalltalkImage>snapshot:andQuit: 0x589aa238: a(n) SmalltalkImage

0x5ad3f0c0 s [] in ReleaseBuilder class>saveAndQuit 0x58994140: a(n) ReleaseBuilder

0x5ad3f198 s WorldState>runStepMethodsIn: 0x58d9bf80: a(n) WorldState

0x5ad3f228 s PasteUpMorph>runStepMethods 0x58da3cb8: a(n) PasteUpMorph

0x5ad3f2f8 s [] in WorldState>doOneCycleNowFor: 0x58d9bf80: a(n) WorldState

0x5ad3f358 s [] in ActiveWorldVariable class(DynamicVariable class)>value:during: 0x58d8f788: a(n) ActiveWorldVariable

0x5ad3f3d8 s FullBlockClosure(BlockClosure)>ensure: 0x5ad3f438: a(n) FullBlockClosure

0x5ad3f4c0 s ActiveWorldVariable class(DynamicVariable class)>value:during: 0x58d8f788: a(n) ActiveWorldVariable

0x5ad3f5b8 s [] in ActiveWorldVariable class>value:during: 0x58d8f788: a(n) ActiveWorldVariable

0x5ad3f688 s FullBlockClosure(BlockClosure)>ensure: 0x5ad3f6e8: a(n) FullBlockClosure

0x5ad3f768 s ActiveWorldVariable class>value:during: 0x58d8f788: a(n) ActiveWorldVariable

0x5ad3f860 s PasteUpMorph>becomeActiveDuring: 0x58da3cb8: a(n) PasteUpMorph

0x5ad3f460 s WorldState>doOneCycleNowFor: 0x58d9bf80: a(n) WorldState

0x5ad3f548 s WorldState>doOneCycleFor: 0x58d9bf80: a(n) WorldState

0x5ad3f628 s PasteUpMorph>doOneCycle 0x58da3cb8: a(n) PasteUpMorph

0x5ad3f708 s [] in MorphicProject>spawnNewProcess 0x58b5e988: a(n) MorphicProject

0x5ad3f7e8 s [] in FullBlockClosure(BlockClosure)>newProcess 0x5ad3f848: a(n) FullBlockClosure
Most recent primitives (oldest first)
PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#*

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#*

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#-

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BoxedFloat64>>#+

PrimitiveFailure BoxedFloat64

PrimitiveFailure BoxedFloat64

BitBlt>>#copyBits

BitBlt>>#copyBits

BitBlt>>#copyBits

Behavior>>#basicNew:

BitBlt>>#copyBits

Number>>#@

Number>>#@

Behavior>>#basicNew

SmallInteger>>#-

SmallInteger>>#-

StackOverflow

BitBlt>>#copyBits

Behavior>>#basicNew

BitBlt>>#copyBits

BitBlt>>#copyBits

BitBlt>>#copyBits

BitBlt>>#copyBits

BitBlt>>#copyBits

BitBlt>>#copyBits

BitBlt>>#copyBits

StackOverflow

BitBlt>>#copyBits

StackOverflow

BitBlt>>#copyBits

StackOverflow

BitBlt>>#primDisplayString:from:to:map:xTable:kern:

BitBlt>>#primDisplayString:from:to:map:xTable:kern:

BitBlt>>#copyBits

BitBlt>>#copyBits

StackOverflow

BitBlt>>#copyBits

Behavior>>#basicNew

BitBlt>>#primDisplayString:from:to:map:xTable:kern:

BitBlt>>#primDisplayString:from:to:map:xTable:kern:

Behavior>>#basicNew

StackOverflow

StackOverflow

StackOverflow

Object>>#shallowCopy

Object>>#perform:with:

BitBlt>>#copyBits

BitBlt>>#copyBits

BitBlt>>#copyBits

BitBlt>>#copyBits

BitBlt>>#copyBits

FullBlockClosure>>#value:

BitBlt>>#copyBits

FullBlockClosure>>#value:

FullBlockClosure>>#value:

Behavior>>#basicNew

StackOverflow

StackOverflow

StackOverflow

StackOverflow

StackOverflow

StackOverflow

StackOverflow

StackOverflow

BitBlt>>#copyBits

PrimitiveFailure GrafPort

Behavior>>#basicNew

BitBlt>>#copyBits

FullBlockClosure>>#value

BitBlt>>#primDisplayString:from:to:map:xTable:kern:

BitBlt>>#primDisplayString:from:to:map:xTable:kern:

CompactCode
stack page bytes 8192 available headroom 6888 minimum unused headroom 7048
(Segmentation fault)

Aborted (core dumped)

This a regression from the previous VM release (202312181441) where the binary appears to operate correctly on my stack.

32-bit Stack VM works fine.
32-bit Debug Cog VM also works fine, so it's a Heisenbug! 🎉

Can anybody else reproduce this or is this my system being weird? Could this be related to my multiarch setup or not really? Should we have better CI to spot such issues earlier?

[marceltaeumel]

[...] installed the required 32-bit libraries (multiarch) on my Ubuntu 24.04 64-bit system [...]

It would be helpful to try this on a regular 32-bit Ubuntu or comparable 32-bit Linux.

[cstes]

I'll give it a try on openSUSE Tumbleweed Linux 32bit or Linux Slackware Current 32bit.

[cstes]

Perhaps this issue is related to issue #762 ? Anyway I tested on an openSUSE Tumbleweed Linux 32bit system. The system is Intel Pentium and it has AMD/ATI graphics (supported by X11 using vesa/fb). It has 1 GB (one gigabyte) of RAM. The Linux kernel is 7.0.12-1-pae and C compiler is GCC 15.3. I compiled opensmalltalk-vm latest version (from VMMaker.oscog-eem.3766) and built a stack-spur and cog-spur VM from the building/linux32x86 subdirectory using the mvm scripts. I modified the mvm script to configure --without-gl (I built without OpenGL support) and I installed libX11-devel and libXrandr-devel to build a vm-display-X11 plugin. The stack-spur VM runs fine and also the cog-spur VM seems to start up but indeed the cog-spur vm seems to crash after a few seconds. So initially it starts up the Squeak6.1beta 23712-32bit image correctly but whereas the stack-spur 32bit opens this Squeak6.1beta 23712-32bit image and remains stable, indeed also for my test, the cog-spur crashes. My interest is whether the classical VM (for running Squeak V4, the classical VM from squeakvm.org has the same problem) so I'll give classical VM 4.21.3 a try later on openSUSE Tumbleweed (https://download.opensuse.org/ports/i586/tumbleweed/).

[cstes]

I tested on openSUSE Leap 16.1 AMD64 to compare with the Tumbleweed installation (openSUSE TumbleWeed is a rolling release and differs from openSUSE Leap 16.1). Those openSUSE distributions also differ from SUSE Entreprise Linux by the way. Anyway ... the test on Leap 16.1 AMD64 was useful because I noticed some interesting compile errors. So I went back to Tumbleweed Linux 7.0.12-1-pae with GCC 15.3 and set as compiler in the mvm script : gcc -O -std=gnu17 -fpermissive. With those flags (presumably the -std=gnu17 -fpermissive -O instead of -O2 is important) the mvm script in the building/linux32x86 directory squeak.cog.spur produces a 32 bit VM that runs the Squeak6.1beta 23712-32bit image correctly, it starts up and it does NOT immediately segfaults after a few seconds. Also when I revert and check out older commits like VMMaker.oscog-eem.3590 from august last year 2025 , I get different results. I tested commit hash e90779d because last year I ran a 32bit test on a physical Linux machine with the VM VMMaker.oscog-eem.3590 from last year.

[cstes]

The classical VM 4.21.3 also compiles on Tumbleweed with GCC 15.3 and with kitware cmake 4.2.3. For using cmake 4.2.3 some special -D is required to support the cmake 4 build system. The classical VM 4.21.3 also compiles on openSUSE Leap 16.1 AMD64 and it opens both on Tumbleweed 32bit and Leap 16.1 64bit , it opens the Squeak4.6-15118 from https://files.squeak.org/4.6/Squeak4.6-15118.zip. There is a problem to run the Squeak SSL tests on OpenSSL 3.5.3.

[cstes]

I've tested on SLES 11 SP4 for i586/i686 (Intel 32 bit) and the classical VM (for Squeak 4.6 15118 or update 15120) does not segfault. However I've also tested on Solaris 11 64bit where I built a -m32 32bit executable for Cog VM and on Solaris Cog VM also crashes. The latter is a 32bit ELF executable on the 64bit unix kernel. Maybe it is possible to find differences later between the current VM and older VM's: I tested commit hash e90779d because last year I ran a 32bit test on a physical Linux and a physical Solaris machine with the VM VMMaker.oscog-eem.3590 from last year which was OK at that time.