Missing dependencies randomly / including custom modules

[aurnik]

For some reason, every time I deploy I'll randomly be missing dependencies. And it's different each time. Here are my settings

dockerizePip: non-linux
vendor: ../custom_libraries
layer: true

For whatever reason, each time I deploy I'm missing a dependency, or I'm getting an AttributeError about the custom dependency even though testing locally with those same dependencies works fine.
I should add that trying to include the custom dependency as a line in requirements.txt didn't work and I would get an error that the file wasn't found even though the path it was outputting was the exact path.

Appreciate any guidance on this