title: What is the meaning of these error messages in running pivot_wider() in RStudio?
body: <p>I'm a newbie in R. Is there anyone who can help me?</p>
  <p>I import a CSV of extract of stackoverflow data from,</p>
  <p><code>s &lt;- read_csv(&quot;https://www.ics.uci.edu/~duboisc/stackoverflow/answers.csv&quot;)</code></p>
  <p>Then, I separate different values in 'tags' column into rows,</p>
  <p><code>ss1 &lt;- separate_rows(ss, tags)</code></p>
  <p>Then, I apply <code>pivot_wider()</code> on 'tags' column,</p>
  <p><code>ss2 &lt;- pivot_wider(ss1, names_from = tags, values_from = qs)</code></p>
  <p>The following error messages are shown,</p>
  <blockquote>
  <p>Error: Internal error in <code>compact_rep()</code>: Negative <code>n</code> in <code>compact_rep()</code>.
  Run <code>rlang::last_error()</code> to see where the error occurred.
  In addition: Warning messages:
  1: Values are not uniquely identified; output will contain list-cols.</p>
  <ul>
  <li>Use <code>values_fn = list</code> to suppress this warning.</li>
  <li>Use <code>values_fn = length</code> to identify where the duplicates arise</li>
  <li>Use <code>values_fn = {summary_fun}</code> to summarise duplicates
  2: In nrow * ncol : NAs produced by integer overflow</li>
  </ul>
  </blockquote>
  <p>I have searched the different keywords in these messages but am not able to find out the overall meaning of these errors. Is there anyone who can help me? Thanks.</p>