title: How do I install packages from source on macOS?
body: <p>I had some problems with knitting the file, so I reinstalled it. I installed the latest version of R studio and it required me install xfun package. I installed it a lot of time but it is still not working. I attached the feedback below.</p>
  <p><img src="https://i.stack.imgur.com/fSV1n.png" alt="enter image description here" /></p>