title: I need to switch to an old version of R to run one script
body: <p>I am trying to run a script that was build on an older version of R.  It runs on one computer, which is running R/3.4.4. It breaks on another, running R/3.6.3.  The author has an issue checked out on his github to fix this (I think), but he's finishing his PhD so that could happen in two months, two years, or never.</p>
  <p>I installed R/3.4.4 in my <code>$HOME/.local</code> path (the other is in <code>/usr/bin</code>). I just can't figure out how to temporarily point to the version in .local when I run this script.  I tried setting R_HOME with <code>export R_HOME=$HOME/.local</code> but R ignores that.</p>
  <p>I am sure this has been asked before, but I can't find anything that doesn't involve RStudio.  I don't have RStudio on my WSL (running Ubuntu 20.04), so I need a terminal-based solution.</p>
  <p>Can someone explain how to do this?  I feel really dense and really exhausted. Thank you.</p>