Maya crashing hard; Error: SIGBUS -- Bus error (bad memory access)

[joostkonemann]

When rendering a sequence, Maya crashes hard without CER after some successful frames. The Arnold log file shows the following error:

ERROR | signal caught: SIGBUS -- Bus error (bad memory access)

What could be causing this?

From a successful frame:

00:00:00 1975MB | rendering image at 960 x 540, 6 AA samples
00:00:00 1975MB | AA samples max <disabled>
00:00:00 1975MB | AA sample clamp <disabled>
00:00:00 1975MB | diffuse samples 4 / depth 1
00:00:00 1975MB | specular samples 2 / depth 1
00:00:00 1975MB | transmission samples 2 / depth 8
00:00:00 1975MB | volume indirect <disabled by depth>
00:00:00 1975MB | total depth 10
00:00:00 1975MB | bssrdf samples 2
00:00:00 1975MB | transparency depth 10
00:00:00 1975MB | initializing 42 nodes ...
00:00:00 1978MB WARNING | [polymesh] pCylinderShape1: discarded 1 duplicate deformation keys
00:00:00 1978MB WARNING | [polymesh] extensionShape: discarded 1 duplicate deformation keys
00:00:00 1981MB WARNING | [polymesh] extrudevolume1: discarded 1 duplicate deformation keys
00:02:14 2405MB | creating root object list ...
00:02:14 2405MB | node initialization done in 2:13.81 (multithreaded)
00:02:14 2405MB | updating 43 nodes ...

Same part of the log file for a crash:

00:00:00 1975MB | rendering image at 960 x 540, 6 AA samples
00:00:00 1975MB | AA samples max <disabled>
00:00:00 1975MB | AA sample clamp <disabled>
00:00:00 1975MB | diffuse samples 4 / depth 1
00:00:00 1975MB | specular samples 2 / depth 1
00:00:00 1975MB | transmission samples 2 / depth 8
00:00:00 1975MB | volume indirect <disabled by depth>
00:00:00 1975MB | total depth 10
00:00:00 1975MB | bssrdf samples 2
00:00:00 1975MB | transparency depth 10
00:00:00 1975MB | initializing 42 nodes ...
00:00:00 1978MB ERROR | signal caught: SIGBUS -- Bus error (bad memory access)
00:00:00 1978MB WARNING | [polymesh] pCylinderShape1: discarded 1 duplicate deformation keys

00:00:00 1978MB WARNING | [polymesh] extensionShape: discarded 1 duplicate deformation keys
00:00:00 1981MB WARNING | [polymesh] extrudevolume1: discarded 1 duplicate deformation keys

Joost

[Stephen.Blair]

Unfortunately, it's not possible to tell from that limited information.

If the scene has procedurals, it could be related to them. Procedurals (standins) are processed during node initialization. Setting the log verbosity to Debug will print information about the procedurals and ass files being loaded.

Otherwise, it could be something specific to the scene Or a system-specific issue; we don't get many sigbus reports.

Can you reproduce consistently?

For testing, I would do a command-line render, to avoid crashing Maya.

[joostkonemann]

I'm suspecting an aiVolume referring to a VDB sequence to be causing the issue. Though, a quick test with ultra-low sampling settings to get more frames tested quickly didn't trigger the error. I'm also trying to figure out if it could be related to the project being on an external SSD.

[joostkonemann]

I've got a new log with more info:

00:00:01 2099MB | rendering image at 1280 x 720, 4 AA samples
00:00:01 2099MB | AA samples max <disabled>
00:00:01 2099MB | AA sample clamp <disabled>
00:00:01 2099MB | diffuse samples 3 / depth 1
00:00:01 2100MB | specular samples 2 / depth 1
00:00:01 2100MB | transmission samples 2 / depth 8
00:00:01 2100MB | volume indirect samples 3 / depth 1
00:00:01 2100MB | total depth 10
00:00:01 2100MB | bssrdf samples 2
00:00:01 2100MB | transparency depth 10
00:00:01 2100MB | initializing 48 nodes ...
00:00:01 2101MB ERROR | signal caught: SIGSEGV -- Invalid memory reference
****
* Arnold 5.3.0.2 [f7602f75] darwin clang-5.0.0 oiio-2.1.0 osl-1.11.0 vdb-4.0.0 clm-1.0.3.513 rlm-12.4.2 2019/04/09 17:09:03
00:00:01 2102MB WARNING | [polymesh] pPlaneShape1: discarded 1 duplicate deformation keys
00:00:01 2102MB WARNING | [polymesh] pCylinderShape1: discarded 1 duplicate deformation keys
00:00:01 2102MB WARNING | [polymesh] extensionShape: discarded 1 duplicate deformation keys
00:00:01 2105MB WARNING | [polymesh] extrudevolume1: discarded 1 duplicate deformation keys
* CRASHED at 00:00:00
* signal caught: SIGSEGV -- Invalid memory reference
*
* backtrace:
* 0 0x000000015f310cf3 [libai.dylib]
*
* loaded modules:
* 0x000000015cfdd000 libai.dylib
****
Stack trace:
4 libDataModel.dylib 0x000000010c7fafbe TDNselectionListIterator::doNext() + 46
5 libDataModel.dylib 0x000000010c7faee9 TDNselectionListIterator::next() + 25
6 libShared.dylib 0x000000010e6aa478 TfileInfoCmd::~TfileInfoCmd() + 53864
7 libCommandEngine.dylib 0x000000010b4bae4d TpythonInterpreter::dispatchMayaCommand(TmetaCommand&, _object*, _object*) + 525
8 Python 0x00000001164deebe PyEval_EvalFrameEx + 30206
9 Python 0x00000001164e3e82 fast_function + 274
10 Python 0x00000001164deab4 PyEval_EvalFrameEx + 29172
11 Python 0x00000001164d75b2 PyEval_EvalCodeEx + 1538
12 Python 0x00000001164d6fa6 PyEval_EvalCode + 54
13 libCommandEngine.dylib 0x000000010b4b99a0 TpythonInterpreter::executeCommand(Tstring const&, bool, bool, TinterpreterResult*) + 784
14 libOpenMaya.dylib 0x000000012efb7d84 Autodesk::Maya::OpenMaya20190000::MGlobal::executePythonCommand(Autodesk::Maya::OpenMaya20190000::MString const&, Autodesk::Maya::OpenMaya20190000::MString&, bool, bool) + 164
15 libmtoa_api.dylib 0x0000000161128a60 Initialize(AtNode*) + 144
16 libai.dylib 0x000000015f25b0cc AiShaderGlobalsEdgeLength + 6285084
Fatal Error. Attempting to save in /var/folders/3v/sss4h8p115bfkw7yvvsqfdq40000gn/T/joost.20190430.1220.ma
Writing crash report in /var/folders/3v/sss4h8p115bfkw7yvvsqfdq40000gn/T/joost.20190430.1220.crash
00:01:17 2137MB | [volume] auto detected velocity grid "v"
00:01:27 2143MB | [volume] maximum velocity displacement: 0.016667 (max velocity: 1.000000, outlier threshold: 0.001000)
00:01:27 2143MB | [volume] volume padding: 0.016667 (user: 0.000000)
00:02:02 2157MB | [volume] dilation count: 10
00:02:05 2296MB | [volume] aiVolumeShape: auto bounds from volume plugin: [ -1.127667 -2.671667 -1.233667 ] -> [ 4.133667 0.343667 1.229667 ]
00:02:05 2296MB | [volume] aiVolumeShape: using volume plugin reported step size of 0.002000

[Stephen.Blair]

So maybe it's something about the VDB sequence. If you can send a scene and a vdb to support, so we can reproduce the problem, then we can investigate.

If you crash with just the volume in the scene, then you could send that simplified scene.