Permission denied when writing a file to the filesystem in Python

In the past 24 hours we have had three reports of permission denied results after a deploy where minimal and unrelated changes were made to their application.

The common thread: each was using a buildpack. If nothing else materially changed, it is quite possible that the change was in the buildpack. If this is urgent, seeking out the authors of the buildpack might be worthwhile.

I would recommend exploring a Dockerfile. The following will get you started: https://community.fly.io/t/flask-app-deploy-error-smoke-checks-error-app-crashing/18487/5 . If you have any questions, you can ask them here.