Monterey 12.7.6 error vspipe exited with signal 4 (unknown)

[MacNB]

Vapourbox release 1.0.0
On Macpro5,1 running Monterey 12.7.6, immediately errors after loading input file.

Log file:

ERROR: Preview generation failed (exit code 1):
Preview: source frame 0 (fps: 25.00)
Preview: source frame 0 (window 0..5, local 0, output index 0) seek 0.000000s (720x576 yuv422p)
Loaded template from: "/Applications/VapourBox.app/Contents/MacOS/../Resources/templates/pipeline_template.vpy"
Loaded template from: "/Applications/VapourBox.app/Contents/MacOS/../Resources/templates/preview_template.vpy"
OpenCL auto-enabled but no usable device detected — falling back to CPU NNEDI3 (set the OpenCL option to force it)
Generated preview script: "/var/folders/8m/783tgb553p1b8k53kprmvfgh0000gn/T/0b39f6aa-0873-494f-9f91-7bc1bf7e85a4_preview.vpy"
Error generating preview: vspipe exited with signal 4 (unknown)

[2026-09-11T21:02:17.724731] Starting preview generation for frame 0
Preview: source frame 0 (fps: 25.00)
Preview: source frame 0 (window 0..5, local 0, output index 0) seek 0.000000s (720x576 yuv422p)
Loaded template from: "/Applications/VapourBox.app/Contents/MacOS/../Resources/templates/pipeline_template.vpy"
Loaded template from: "/Applications/VapourBox.app/Contents/MacOS/../Resources/templates/preview_template.vpy"
OpenCL auto-enabled but no usable device detected — falling back to CPU NNEDI3 (set the OpenCL option to force it)
Generated preview script: "/var/folders/8m/783tgb553p1b8k53kprmvfgh0000gn/T/0b39f6aa-0873-494f-9f91-7bc1bf7e85a4_preview.vpy"
Error generating preview: vspipe exited with signal 4 (unknown)
[2026-09-11T21:02:18.004631] Process exited with code 1, output size: 0 bytes

Any idea for the cause of this error ?

[StuartCameronCode]

Thanks for the detailed log — that's very useful.

vspipe exited with signal 4 is SIGILL (illegal instruction). That's a specific, known failure class here: a plugin executed a CPU instruction (typically AVX/AVX2) that the machine doesn't actually have. We've hit this before on other old CPUs (a Celeron J4105 and a Core i7 870), and a Mac Pro 5,1's Xeon (Nehalem/Westmere, 2009–2012) is exactly that class of hardware — it predates AVX entirely.

The two previous instances of this we found and fixed (a zsmooth plugin build issue, and a CTMF auto-detect issue) don't quite line up with your log, though — your preview log shows only the default deinterlace pass running (QTGMC "Slower" preset, falling back from OpenCL to CPU NNEDI3), and neither of those two fixed plugins are touched by that pass. So this looks like the same type of bug, but in a different plugin we haven't isolated yet — most likely something QTGMC's motion analysis step depends on.

To narrow it down, could you help with a few things?

1. CPU features: run the bundled worker with --probe-cpu and paste the output. From a Terminal:

   /Applications/VapourBox.app/Contents/MacOS/vapourbox-worker --probe-cpu
   

2. Bisect the pass: does the crash still happen if you lower the deinterlace preset to "Very Fast" (skips most motion analysis), or if you disable deinterlacing entirely?
3. The generated script: if you can, set Settings → General → Temporary Files to a folder you can find afterward, reproduce the crash, and attach the .vpy file it generates — that will let us see exactly which plugin call is failing.

This will help us reproduce and fix it properly rather than guessing at which plugin needs the same CPU-baseline treatment as the last two.

[MacNB]

I suspected the AVX/AX2 issue and thought you had tried to avoid the use of these instruction set in the past.

1. CPU Feature test:
   the --probe-cpu option does not work:

MacNB@Mac-Pro-368 ~ % /Applications/VapourBox.app/Contents/MacOS/vapourbox-worker --probe-cpu
error: unexpected argument '--probe-cpu' found

  tip: a similar argument exists: '--probe-opencl'

Usage: vapourbox-worker --probe-opencl

For more information, try '--help'.
MacNB@Mac-Pro-368 ~ %

--probe-opencl result in false:

MacNB@Mac-Pro-368 ~ % /Applications/VapourBox.app/Contents/MacOS/vapourbox-worker --probe-opencl
{"knlm":false,"opencl":false}
MacNB@Mac-Pro-368 ~ % 

2. Setting deinterlace to Very Fast or even disabling it makes no difference.

3. I changed the temp folder path to /Users/Shared/vb-tmp but there are no.vpyscripts in there but only a bunch of thumbnails. Seems to failing before any plugins are called ?
   The log does not match what's in the temp folder. E.g. log shows /Users/Shared/vb-tmp/65e8686a-c52c-4543-b2d9-fce0b8deb30e_preview.vpy but there's another folder instead /Users/Shared/vb-tmp/vapourbox_preview_1789202420780 that is not listed in the log:

MacNB@Mac-Pro-368 ~ % ls -l /Users/Shared/vb-tmp                                
total 0
drwxr-xr-x  23 macnb  wheel  736 12 Sep 09:42 vapourbox_preview_1789202420780
MacNB@Mac-Pro-368 ~ % 

That folder just contains a bunch of thumbnails and no script files.

Here's the log:

ERROR: Preview generation failed (exit code 1):
Preview: source frame 0 (fps: 25.00)
Preview: source frame 0 (window 0..5, local 0, output index 0) seek 0.000000s (720x576 yuv422p)
Loaded template from: "/Applications/VapourBox.app/Contents/MacOS/../Resources/templates/pipeline_template.vpy"
Loaded template from: "/Applications/VapourBox.app/Contents/MacOS/../Resources/templates/preview_template.vpy"
Generated preview script: "/Users/Shared/vb-tmp/65e8686a-c52c-4543-b2d9-fce0b8deb30e_preview.vpy"
Error generating preview: vspipe exited with signal 4 (unknown)


[2026-09-12T09:42:01.793233] Starting preview generation for frame 0
Preview: source frame 0 (fps: 25.00)
Preview: source frame 0 (window 0..5, local 0, output index 0) seek 0.000000s (720x576 yuv422p)
Loaded template from: "/Applications/VapourBox.app/Contents/MacOS/../Resources/templates/pipeline_template.vpy"
Loaded template from: "/Applications/VapourBox.app/Contents/MacOS/../Resources/templates/preview_template.vpy"
Generated preview script: "/Users/Shared/vb-tmp/65e8686a-c52c-4543-b2d9-fce0b8deb30e_preview.vpy"
Error generating preview: vspipe exited with signal 4 (unknown)
[2026-09-12T09:42:02.029095] Process exited with code 1, output size: 0 bytes

[StuartCameronCode]

Thanks — that's useful, and it changes the picture. The crash still happening with deinterlacing fully disabled rules out QTGMC's plugins entirely, so this isn't the same kind of bug as the previous two. (Also, my mistake on --probe-cpu — that flag was added a week after the v1.0.0 build you're running, so it's not in your copy. Sorry for the dead end.)

Since this is a native crash with no Python traceback, the fastest way to identify exactly which plugin is at fault is macOS's own crash report:

1. Reproduce the crash once more.
2. Open Console.app → Crash Reports in the sidebar (or look in ~/Library/Logs/DiagnosticReports/) for the newest report — it'll be named something like Python-<date>-<time>.ips.
3. Paste the "Crashed Thread" backtrace, plus the "Binary Images" line for any frame whose path contains VapourBox.app.

That will name the exact library that's faulting instead of us guessing further.

[StuartCameronCode]

Also, a new 1.1 release is out, let me know if that changes anything.

[MacNB]

Looked in Console for crash reports related to Vapourbox.
There were no Python reports but several for vspipe.bin.

Looks like MVDegrains within libmvtools.dylib is using AVX2 instruction causing CPU SIGILL

Please see attache .ips file

vspipe-bin-2026-09-13-193015.ips.zip

UPDATE:
upgrading to Vapaourbox 1.1.0 fails in exactly the same way in the same MVDegrains function