Blender 5.1.2 dumps core with no clear cause - fix

Basic Help & Support
1

Used blender a couple of weeks ago and it worked fine. Tried opening it today, and it crashed with some python errors about plugins. So I removed those from ~/.config/blender/5.1/extensions/user_default but no help. Uninstalled and reinstalled Blender and its dependencies, same. Other than a blank window appearing for a few seconds, the following was all I saw, even with debug enabled:

me@mine ~ $ blender -d
Switching to fully guarded memory allocator.
Blender 5.1.2
Build: 2026-05-19 10:38:26 Linux Release
argv[0] = blender
argv[1] = -d
Add-on not loaded: "space_view3d_pie_menus", cause: No module named 'space_view3d_pie_menus'
Add-on not loaded: "space_view3d_modifier_tools", cause: No module named 'space_view3d_modifier_tools'
Add-on not loaded: "object_boolean_tools", cause: No module named 'object_boolean_tools'
Add-on not loaded: "add_mesh_extra_objects", cause: No module named 'add_mesh_extra_objects'
Add-on not loaded: "add_curve_extra_objects", cause: No module named 'add_curve_extra_objects'
Add-on not loaded: "add_mesh_BoltFactory", cause: No module named 'add_mesh_BoltFactory'
Add-on not loaded: "mesh_looptools", cause: No module named 'mesh_looptools'
Add-on not loaded: "bl_ext.user_default.nd", cause: No module named 'bl_ext.user_default.nd'
Add-on not loaded: "bl_ext.user_default.CAD_Sketcher", cause: No module named 'bl_ext.user_default.CAD_Sketcher'
Add-on not loaded: "bl_ext.user_default.fabex", cause: No module named 'bl_ext.user_default.fabex'
Writing: /tmp/blender.crash.txt
Segmentation fault         (core dumped) blender -d

me@mine ~ $ cat /tmp/blender.crash.txt
# Blender 5.1.2, Commit date: 2026-05-18 13:43, Hash ec6e62d40fa9

# backtrace
blender(+0x25a94fd) [0x62fb99ed24fd]
blender(+0x18bc633) [0x62fb991e5633]
/usr/lib/libc.so.6(+0x3e270) [0x7683eb132270]
/usr/lib/libSPIRV-Tools-opt.so(+0x5b006) [0x7683e91d6006]
/usr/lib/libSPIRV-Tools-opt.so(_ZNSt17_Function_handlerIFbPKjEZNK8spvtools3opt11Instruction11ForEachInIdERKSt8functionIFvS1_EEEUlS1_E_E9_M_invokeERKSt9_Any_dataOS1_+0x38) [0x7683e91cec78]
/usr/lib/libSPIRV-Tools-opt.so(_ZN8spvtools3opt17AggressiveDCEPass21AddOperandsToWorkListEPKNS0_11InstructionE+0xb5) [0x7683e91d5e95]
/usr/lib/libSPIRV-Tools-opt.so(_ZN8spvtools3opt17AggressiveDCEPass15ProcessWorkListEPNS0_8FunctionE+0x5a) [0x7683e91dad1a]
/usr/lib/libSPIRV-Tools-opt.so(_ZN8spvtools3opt17AggressiveDCEPass13AggressiveDCEEPNS0_8FunctionE+0xb4) [0x7683e91daec4]
/usr/lib/libSPIRV-Tools-opt.so(_ZN8spvtools3opt17AggressiveDCEPass11ProcessImplEv+0xd9) [0x7683e91dcc69]
/usr/lib/libSPIRV-Tools-opt.so(_ZN8spvtools3opt4Pass3RunEPNS0_9IRContextE+0x2a) [0x7683e9315e7a]
/usr/lib/libSPIRV-Tools-opt.so(_ZN8spvtools3opt11PassManager3RunEPNS0_9IRContextE+0x15e) [0x7683e93171fe]
/usr/lib/libSPIRV-Tools-opt.so(_ZNK8spvtools9Optimizer3RunEPKjmPSt6vectorIjSaIjEEP23spv_optimizer_options_t+0x189) [0x7683e9311369]
/usr/lib/libshaderc_shared.so.1(+0x14f1d) [0x7683ff6e3f1d]
/usr/lib/libshaderc_shared.so.1(+0x167c9) [0x7683ff6e57c9]
/usr/lib/libshaderc_shared.so.1(shaderc_compile_into_spv+0x12) [0x7683ff6e6052]
blender(+0x299ec31) [0x62fb9a2c7c31]
blender(+0x299c3e9) [0x62fb9a2c53e9]
blender(+0x272469b) [0x62fb9a04d69b]
blender(+0x2725b97) [0x62fb9a04eb97]
blender(+0x288d356) [0x62fb9a1b6356]
blender(+0x288d70d) [0x62fb9a1b670d]
/usr/lib/libstdc++.so.6(+0xea659) [0x7683eb3fa659]
/usr/lib/libc.so.6(+0x97739) [0x7683eb18b739]
/usr/lib/libc.so.6(+0x11bedc) [0x7683eb20fedc]

# Python backtrace
me@mine ~ $

If this happens to you, and you are using the Vulkan backend, try this:

blender -d --gpu-backend opengl

If it now works, set the System - Display Graphics - Backend to OpenGL. Seems like a Vulkan / video driver issue.

2 Likes
2

Good to know. I was already using opengl as the backend and blender fired right up. However, I did change it to vulkan and can confirm that blender does in fact fail. So thank you for this information. Should be helpful to more than one person.

3

Blender released LTS version 5.2 with a good number of fixes for several kind of crashes. It should be available in the official repos soon.

4

When Vulkan works, Blender is able to take advantage of its modern framework and significantly boost performance, so it is the better option. If it is working.

The last system update did bork my Nvidia driver somehow, but I’d thought that was all fixed.. maybe not.

Not sure if it is purely a Vulkan issue. Have vulkan-tools installed, so ran vulkaninfo and vkcube, both of which worked, except the vkcube is a little stuttery for some reason.

In any case, Blender 5.2 can’t get here fast enough. :slight_smile:

5

Well Blender 5.2 didn’t help. What did help was this thread: Blender crashes on startup when using Vulkan backend / Applications & Desktop Environments / Arch Linux Forums

Seems there is an upstream issue with spirv-tools. Quick fix is to downgrade that to the previous version. This works for me:

sudo pacman -U /var/cache/pacman/pkg/spirv-tools-1:1.4.341.0-2-x86_64.pkg.tar.zst

1 Like