title: AWS SAM CLI ignoring my Python dependencies during build, package, and deploy
body: <p>I'm trying to deploy an AWS Lambda function with the SAM CLI tool, from MacOS, not using Docker containers.</p>
  
  <ul>
  <li>SAM CLI version 0.4.0</li>
  <li>Python 3.8 runtime for Lambda function</li>
  <li>Python 3.7 installed locally on MacOS</li>
  <li>I have a <code>requirements.txt</code> file, in the same directory as my Lambda function file</li>
  </ul>
  
  <h2>Requirements.txt</h2>
  
  <pre><code>boto3
  botostubs
  </code></pre>
  
  <h2>Deploy Script (PowerShell)</h2>
  
  <pre><code>sam build --template-file $InputTemplate
  sam package --region $AWSRegion --template-file $InputTemplate --profile $ProfileName --s3-bucket $BucketName --output-template-file $OutputTemplate
  sam deploy --region $AWSRegion --profile $ProfileName --template-file $OutputTemplate --stack-name $StackName --capabilities CAPABILITY_NAMED_IAM
  </code></pre>
  
  <h2>Actual Behavior</h2>
  
  <p>SAM CLI is ignoring my <code>requirements.txt</code> file, and only deploying my source code. This results in the following error when I test my function.</p>
  
  <pre><code>{
    "errorMessage": "Unable to import module 'xxxxxxxxxxxxxx': No module named 'botostubs'",
    "errorType": "Runtime.ImportModuleError"
  }
  </code></pre>
  
  <h2>Expected Behavior</h2>
  
  <p>SAM CLI packages up the declared Python dependencies, in <code>requirements.txt</code>, along with my source code.</p>
  
  <p><strong>Question</strong>: How can I ensure that the SAM CLI downloads and packages my Python dependencies, along with my source code? I followed the documentation, to the best of my knowledge.</p>
  
  <p><a href="https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-using-build.html" rel="noreferrer">https://docs.aws.amazon.com/serverless-application-model/latest/developerguide/serverless-sam-cli-using-build.html</a></p>