the time you cannot use an interactive debugger, and often even
print-debugging, i.e. inserting <code>print()</code> and <code>cat()</code> calls into the
code that runs in the background, can be non-trivial.</p>
<p>The new 3.3.0 version of callr aims to help with this, by creating better
error messages and error traces for errors originating from the background
process. In particular, callr now always throws error objects that
contain:</p>
<ul>
<li>the exit status of the R process, if the process terminat