How to debug segmentation fault memory issue??

[mratsim]

Callbacks passed to C need to be in a `{.push stacktrace:off.}` section, maybe 
we can have that implied when we use the `{.cdecl.}` pragma?

See: 
<https://github.com/mratsim/trace-of-radiance/blob/e928285/trace_of_radiance/io/mp4.nim#L115-L126>