title: Where do I find the solver error code definitions for Coin-OR CBC that Pyomo returns?
body: <p>I see <code>ERROR: - Solver (cbc) returned non-zero return code (-9)</code> when running my Pyomo problem.</p>
  
  <p>I have tried <code>solve(instance, tee=True, keepfiles=True, logfile="my.log")</code> but the <code>my.log</code> is not appearing.  I have searched through the Pyomo and cbc github repositories but I do not understand how to trace the error codes.</p>