FastApi app not building

  1. The build is not triggering on push.
  2. I then manually force build and clean cache. It says
  Requested runtime 'python-3.11.4' is not available for this stack (heroku-18). 
  [2023-08-15 19:02:07] │  !     For supported versions, see: 
  [2023-08-15 19:02:07] │ ERROR: failed to build: exit status 1 
  [2023-08-15 19:02:07] │ 
  [2023-08-15 19:02:07] │ 
  [2023-08-15 19:02:07] │ For documentation on the buildpacks used to build your app, please see: 
  [2023-08-15 19:02:07] │ 
  [2023-08-15 19:02:07] │    Python  v2.231.4 
  [2023-08-15 19:02:07] │

Well per the docs in DigitalOcean it says if there is no runtime.txt, it will default on its own version. And I didn’t have one before. Anyways, I added one, and I tried 3.11.3 and 3.11.4, both no good. Keeps failing.

I know DigitalOcean uses heroku buildpack. Not sure what’s going on right here.

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Jon Friesen
DigitalOcean Employee
DigitalOcean Employee badge
August 16, 2023
Accepted Answer


Please consider upgrading your app to the new stack by adding a feature flag to your app spec, located in your app settings tab:

    - buildpack-stack=ubuntu-22

A full app spec example:

name: sample-python
    - buildpack-stack=ubuntu-22
- github:
    branch: main
    repo: digitalocean/sample-python
  http_port: 8080
  instance_count: 1
  instance_size_slug: basic-xxs
  name: web
  - path: /


Bobby Iliev
Site Moderator
Site Moderator badge
August 16, 2023

Hi there,

I could suggest checking if there are any buildpacks upgrades available for your app.

To upgrade all of the app’s and its components’ buildpacks simultaneously, go to the control panel and click on the app with buildpacks you want to upgrade. Then, click on the app’s Overview tab. If any buildpacks have available upgrades, this page has a card titled Buildpack Upgrades Available. To upgrade, click the Deploy Upgrades button in this card. Note that this process redeploys your app.

If there are no buildpack upgrades available, is your repository open-source by any chance? If so, can you share a link here so I could take a look and see if there are any configuration settings that might be causing the problem?



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