Heroku H10 error — Python

Question

I have spent the past 5 hours trying to deploy my app on Heroku and it isn't working...its a python app, and it works perfectly fine when I run it locally.

However, when I deploy to Heroku, I get the following error:

2014-06-19T20:16:28.240849+00:00 heroku[api]: Enable Logplex by cahnda@gmail.com
2014-06-19T20:16:28.240931+00:00 heroku[api]: Release v2 created by cahnda@gmail.com
2014-06-19T20:18:27+00:00 heroku[slug-compiler]: Slug compilation started
2014-06-19T20:19:20+00:00 heroku[slug-compiler]: Slug compilation failed: failed to          compile Python app

2014-06-19T20:21:33+00:00 heroku[slug-compiler]: Slug compilation started
2014-06-19T20:22:12+00:00 heroku[slug-compiler]: Slug compilation failed: failed to compile Python app
2014-06-19T20:23:28+00:00 heroku[slug-compiler]: Slug compilation started
2014-06-19T20:24:11+00:00 heroku[slug-compiler]: Slug compilation failed: failed to compile Python app
2014-06-19T20:27:12+00:00 heroku[slug-compiler]: Slug compilation started
2014-06-19T20:27:50+00:00 heroku[slug-compiler]: Slug compilation finished
2014-06-19T20:27:50.659666+00:00 heroku[api]: Deploy 95e0979 by cahnda@gmail.com
2014-06-19T20:27:50.577906+00:00 heroku[api]: Scale to web=1 by cahnda@gmail.com
2014-06-19T20:27:50.659724+00:00 heroku[api]: Release v3 created by cahnda@gmail.com
2014-06-19T20:27:57.641496+00:00 heroku[web.1]: State changed from starting to up
2014-06-19T20:27:59.423572+00:00 heroku[web.1]: State changed from up to crashed
2014-06-19T20:27:59.424174+00:00 heroku[web.1]: State changed from crashed to starting
2014-06-19T20:27:56.011407+00:00 heroku[web.1]: Starting process with command `gunicorn app:app`
2014-06-19T20:27:59.409009+00:00 heroku[web.1]: Process exited with status 3
2014-06-19T20:28:06.601752+00:00 heroku[web.1]: State changed from starting to crashed
2014-06-19T20:28:08.016745+00:00 heroku[router]: at=error code=H10 desc="App crashed" 
method=GET path="/" host=secure-fjord-2980.herokuapp.com request_id=9fcc7ffe-3c5b-406c-   aaed-87c9fa8c8523 fwd="68.173.78.212" dyno= connect= service= status=503 bytes=
2014-06-19T20:28:08.265595+00:00 heroku[router]: at=error code=H10 desc="App crashed" 
method=GET path="/" host=secure-fjord-2980.herokuapp.com request_id=e1920daf-4cfc-466d-ba56-7f923ac6c7d9 fwd="68.173.78.212" dyno= connect= service= status=503 bytes=   
2014-06-19T20:28:08.708322+00:00 heroku[router]: **at=error code=H10 desc="App crashed"** 
method=GET path="/favicon.ico" host=secure-fjord-2980.herokuapp.com request_id=a8f085da-ce20-40ed-8882-d1d848538b23 fwd="68.173.78.212" dyno= connect= service= status=503 bytes=

What does this mean? What can I do to fix this? Please help!

Answer 1

H10 errors can be a pain. Because H10 is a generic error and no stack trace is provided, so it's really hard to understand what is going on behind the curtain. I learned, not long time ago, that the fastest way to solve H10 errors ( app crashed ) on Heroku, is by using Sentry .

It sends you the stack trace by email (or you can use the dashboard on the web app).

If your app is a Django app, then you can even skip Sentry and configure ADMINS and emails to send logging reports. See error reporting in Django .