title: Deploy a Python (Dash) app to Heroku using Conda environments (instead of virtualenv)
body: <p>When I run <code>git push heroku master</code> to deploy my app to Heroku I keep getting errors</p>
  
  <blockquote>
    <p>Heroku Push rejected, failed to compile Python app. Could not find a version that satisfies the requirement</p>
  </blockquote>
  
  <p>The problem was that the <code>requirements.txt</code> file I made with</p>
  
  <pre><code>pip freeze &gt; requirements.txt
  </code></pre>
  
  <p>made a dump of my system wide Python libraries instead of just the libraries in my <code>virtualenv</code> (<a href="https://stackoverflow.com/questions/9917628/heroku-push-fails-repeatedly-appears-to-fail-on-installing-bonjour/9917904#9917904">as described here</a>). This was very strange because I froze those requirements from my active virtualenv - this behavior should not have been possible.</p>
  
  <p><code>virtualenv</code> on windows has always slowed me down so I'm ready to try a new environment manager.</p>
  
  <p>I want to use <code>conda</code> but am struggling to deploy with it to Heroku. I followed <a href="https://elements.heroku.com/buildpacks/conda/conda-buildpack" rel="noreferrer">Heroku's instructions for conda build-packs</a> only to get vague/unhelpful errors at build time. </p>
  
  <p>How can I deploy a Python app to Heroku using Conda environments?</p>