Runtime.txt fixes blank heroku build: edge case or PR?

Hi all,
Wondering if this fix is PR-worthy, or just some strange edge case I’ve stumbled upon.

When I git clone mininal-heroku-demo and deploy locally with panel serve, the dashboard renders as expected. When I deploy to heroku as described in the README, however, the resulting heroku web app is just a blank page.

Comparing the heroku build log (and docs) with my local env, I noticed that heroku builds with python 3.6.12 by default, but that my local env was running python 3.7.9.

Adding a runtime.txt file with the contents python-3.7.9 to the build directory fixed this problem for me, and resulted in a functioning heroku deployment.

Wondering if anyone else has encountered this issue? Is it general enough to merit a PR on the heroku demo repo? Could be as simple as a note in the Happy to submit one if so.


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Hi @cisaacstern

Welcome to the community. And thanks for wanting to help improve Panel.

I think that would be a great PR. And i also think a bug could be reported to Panel as Python 3.6 is a supported version as far as i know.


Thanks @Marc, great to be here. (Deleted my first reply, b/c I realized it didn’t make sense!)

Presumably is the best place to report the bug?

I’ll submit a PR for minimal-heroku-demo shortly.


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