RuntimeError: memory access out of bounds when using exec multiple times in a row

[domlija]

Describe the bug
When repeatedly executing an ffmpeg operation (using ffmpeg.exec) either in a loop or manually by clicking a button, after few tens of operations (minimum was 15, maximum was 65 depending on the complexity) the worker dies with RuntimeError: memory access out of bounds error.

To Reproduce
Repeatedly call exec method of the same worker. Reproduced with all exec arguments I tried.

Expected behavior
Worker not dying and completing operations as needed.

Desktop (please complete the following information):

• OS: MacOS
• Browser chrome, safari

Extra

The problem does not happen with reloading the worker between execs.