Opening flowblade causes python3.10 to quit unexpectedly

[Solhex]

Flowblade version: 2.10
MLT version: 7.17.0
Distribution: Fedora Linux 38 (Workstation Edition)
OS type: 64-bit
Desktop Environment: Gnome 44.2
Windowing system: Wayland
Kernel version: Linux 6.3.8-200.fc38.x86_64

Whenever I start-up flowblade or open a previous project I get the error message "python3.10 quit unexpectedly" from problem reporting, which spits out:

reason: python3.10 killed by SIGSEGV
cmdline: /usr/bin/python3 /app/share/flowblade/Flowblade/launch/flowbladegputestrender

Running the flatpak in cmdline with -v, when it starts the error occurs but nothing is printed out. However when opening a previous project it gets stuck loading the project trying to build a certain track, and the following is printed out to the cmdline:

window resized FAILED
Exception in thread Thread-2:
Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
    self.run()
  File "/app/share/flowblade/Flowblade/projectaction.py", line 130, in run
    project = persistance.load_project(self.filename)
  File "/app/share/flowblade/Flowblade/persistance.py", line 470, in load_project
    fill_sequence_mlt(seq, project.SAVEFILE_VERSION)
  File "/app/share/flowblade/Flowblade/persistance.py", line 530, in fill_sequence_mlt
    compositor = mlttransitions.create_compositor(py_compositor.type_id)
  File "/app/share/flowblade/Flowblade/mlttransitions.py", line 433, in create_compositor
    transition_info = mlt_compositor_transition_infos[compositor_type]
KeyError: '##auto_fade_in'

I didn't get this error few weeks before and it operated as expected, and from then I haven't really installed anything that could've messed with my system so I'm at a stump of what could've caused this.

[jliljebl]

These are two different problems

1. Gpu render issue:

reason: python3.10 killed by SIGSEGV
cmdline: /usr/bin/python3 /app/share/flowblade/Flowblade/launch/flowbladegputestrender

This is a bit baffling. Should happen everywhere if happens at all. The GPU render tests launch prosesses that are supposed to crash if some resource is not available, but that does not crash the application when running from developer version, or when running from Flatpak here.

I get e.g.

GPU test results {'NVENC H.264 High Profile / .mp4': 0, 'NVENC HEVC Main10 Profile / .mp4': 0, 'VAAPI H.264 / .mp4': -11}

printed on terminal as test results, and -11 is indeed SIGSEGV. But that is supposed to happen, I do:

        process = subprocess.Popen([sys.executable, respaths.LAUNCH_DIR + "flowbladegputestrender"], stdin=FLOG, stdout=FLOG, stderr=FLOG)
        try:
            out, err = process.communicate(timeout=5)
        except subprocess.TimeoutExpired:
            return -1
 
        return process.returncode

to run the tests and get the return values to find out which GPU render options are available.

But on your Fedora Linux 38, Gnome 44.2, Wayland that crashes the application, don't know why. Python Subprocess API does not indicate that crashing Subprocess.process crashes parent process.

2. Load error:

window resized FAILED
Exception in thread Thread-2:
Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1016, in _bootstrap_inner
    self.run()
  File "/app/share/flowblade/Flowblade/projectaction.py", line 130, in run
    project = persistance.load_project(self.filename)
  File "/app/share/flowblade/Flowblade/persistance.py", line 470, in load_project
    fill_sequence_mlt(seq, project.SAVEFILE_VERSION)
  File "/app/share/flowblade/Flowblade/persistance.py", line 530, in fill_sequence_mlt
    compositor = mlttransitions.create_compositor(py_compositor.type_id)
  File "/app/share/flowblade/Flowblade/mlttransitions.py", line 433, in create_compositor
    transition_info = mlt_compositor_transition_infos[compositor_type]
KeyError: '##auto_fade_in'

This one makes more sense and should be fixable.

[jliljebl]

BTW, is possible for you to test this bug:

reason: python3.10 killed by SIGSEGV
cmdline: /usr/bin/python3 /app/share/flowblade/Flowblade/launch/flowbladegputestrender

running Gnome on XOrg, so we would know if this is Wayland related issue?

[Solhex]

Just tested it on Gnome XOrg and unfourtantely I got the exact same issue.

[jliljebl]

Thanks for doing the test.

It is actually positive result for the project, as it implies that Wayland systems do not crash the app as it is now presented.

[Solhex]

The new update has just fixed the main issue for me, the load error, I'm now back to editing. Thanks!

[thennicke]

I know this is marked as fixed, but I still have the same SIGSEGV issue and get annoying notifications that Python has crashed every time I open Flowblade. See attached image from the problem reporting tool:

If you want any information from me to help resolve this please let me know. I'm on Fedora 41 Wayland, with an AMD GPU. Thanks.

[jliljebl]

I'll reopen and give this some further examination.