求助：Python Flask Heroku应用访问时触发H10（App crashed）崩溃错误

Hey there, that H10 error is one of the most common headaches when deploying Flask apps to Heroku—let’s walk through the most likely fixes step by step:

• Double-check your Procfile
  Heroku needs this file to know how to start your app. Make sure it’s named exactly Procfile (no .txt extension!) and contains a line like:
  web: gunicorn your_main_file_name:your_flask_instance
  For example, if your Flask app is initialized in app.py as app = Flask(__name__), the line should be web: gunicorn app:app.

• Verify your requirements.txt
  Heroku installs dependencies from this file—don’t forget to include all packages your app needs, including flask and gunicorn. Generate it properly with:
  pip freeze > requirements.txt
  Missing dependencies are a top cause of crashes.

• Use the correct port configuration
  Heroku assigns a dynamic port via the PORT environment variable—your Flask app can’t hard-code port 5000. Update your run code to:

  import os
  from flask import Flask
  
  app = Flask(__name__)
  
  # ... your routes ...
  
  if __name__ == "__main__":
      app.run(host='0.0.0.0', port=int(os.environ.get('PORT', 5000)))
  

  The 0.0.0.0 ensures the app listens on all network interfaces, which Heroku requires.

• Dig into the full crash logs
  The router logs you shared only tell you the app crashed, not why. Run this command in your terminal to see real-time, detailed logs:
  heroku logs --tail
  Look for tracebacks (like ImportError or SyntaxError) that point to the exact issue—this is the fastest way to diagnose problems.

• Test locally with Gunicorn
  Before deploying, simulate Heroku’s environment by running your app with Gunicorn locally:
  gunicorn app:app
  If it fails here, fix the issue first before pushing to Heroku—this saves you time debugging on the platform.

Give these steps a shot, and you’ll probably get your app up and running in no time!

内容的提问来源于stack exchange，提问作者Avian