使用Heroku部署Python OpenCv Web应用程序时遇到问题

Question

    Running python -m src.db.create on ⬢ overwatchperfectflex... up, run.1321 (Free)
    Traceback (most recent call last):
      File "/app/.heroku/vendor/lib/python2.7/runpy.py", line 162, in _run_module_as_main
        "__main__", fname, loader, pkg_name)
      File "/app/.heroku/vendor/lib/python2.7/runpy.py", line 72, in _run_code
        exec code in run_globals
      File "/app/src/db/create.py", line 1, in 
        from src.web.server import db
      File "src/web/server.py", line 1, in 
        import cv2
    ImportError: libpng12.so.0: cannot open shared object file: No such file or directory 

Heroku无法识别“ libpng12.so.0”，但是当我在本地运行项目时，没有这种错误。我尝试使用以下构建包：

• https://elements.heroku.com/buildpacks/heroku/heroku-buildpack-apt#buildpack-instructions
• https://elements.heroku.com/buildpacks/diogojc/heroku-buildpack-python-opencv-scipy

但是应用后，它仍然会产生相同的错误