Index: trunk/Ohana/src/opihi/pcontrol/pcontrol.c.in
===================================================================
--- trunk/Ohana/src/opihi/pcontrol/pcontrol.c.in	(revision 18098)
+++ trunk/Ohana/src/opihi/pcontrol/pcontrol.c.in	(revision 28158)
@@ -1,3 +1,5 @@
 # include "pcontrol.h"
+
+# define STDERR_FILE "pcontrol.log"
 
 # define opihi_name "PCONTROL"
@@ -24,4 +26,12 @@
   signal (SIGTSTP, gotsignal);
   signal (SIGTTIN, gotsignal);
+
+  // stdin / stdout are used for communication with pantasks.
+  // redirect stderr so various error messages are saved
+  stderr = freopen (STDERR_FILE, "a", stderr);
+  if (!stderr) {
+      fprintf (stdout, "failed to open %s for error output\n", STDERR_FILE);
+      exit (1);
+  }
 
   rl_readline_name = opihi_name;