title: Azure function Python - error "binding type(s) 'blobTrigger' are not registered"
body: <p>I am trying to run an Azure function locally on my Mac and getting the following error: <code>The binding type(s) 'blobTrigger' are not registered. Please ensure the type is correct and the binding extension is installed.</code></p>
  
  <p>I'm working with <code>Python 3.6.8</code> and have installed <code>azure-functions-core-tools</code> using homebrew (<code>brew tap azure/functions; brew install azure-functions-core-tools</code>). </p>
  
  <p>Setup my <code>local.settings.json</code> file with the expected configuration, so function should be listening to the correct storage container hosted in azure.</p>
  
  <p>Im certain I have not changed any code or configuration files since it was working last week.</p>
  
  <p>host.json file contains:</p>
  
  <pre><code>{
    "version": "2.0",
    "extensionBundle": {
      "id": "Microsoft.Azure.Functions.ExtensionBundle",
      "version": "[1.*, 2.0.0)"
    }
  }
  </code></pre>
  
  <p>function.json file contains:</p>
  
  <pre><code>{
    "scriptFile": "__init__.py",
    "bindings": [
      {
        "name": "xmlblob",
        "type": "blobTrigger",
        "direction": "in",
        "path": "&lt;directory&gt;/{name}",
        "connection": "AzureStorageAccountConnectionString"
      }
    ]
  }
  </code></pre>
  
  <p>requirements.txt file contains:</p>
  
  <pre><code>azure-cosmos==3.1.0
  azure-functions-worker==1.0.0b6
  azure-storage==0.36.0
  azure-storage-blob==2.0.1
  xmljson==0.2.0
  xmlschema==1.0.11
  </code></pre>
  
  <p>Then I run the following commands in my terminal:</p>
  
  <pre><code>1) pip install -r requirements.txt
  2) source .env/bin/activate
  3) func host start
  </code></pre>
  
  <p>I then get the following error:</p>
  
  <pre><code>&lt;Application name&gt;: The binding type(s) 'blobTrigger' are not registered. Please ensure the type is correct and the binding extension is installed.
  </code></pre>