title: :-1: linker command failed with exit code 1 (use -v to see invocation)
body: <p><img src="https://i.stack.imgur.com/lJBos.png" alt="I don't know what does it mean" /></p>
  <p>I was practicing and decided to make food delivery app, I wanted to import firebase, but after downloading cocoapods, even though downloading process was successful I still get this error with linker command.</p>
  <blockquote>
  <p>linker command failed with exit code 1 (use -v to see invocation)</p>
  </blockquote>