More info when plotting fails.

pyglance/glance/plot.py

@@ -74,7 +74,7 @@ def _handle_fig_creation_task(child_figure_function, log_message,
             plt.close(figure)
             del(figure)
         else:
-            LOG.warn("Unable to create plot.")
+            LOG.warn("Unable to create plot {0} ({1}).".format(fullFigName, log_message))
     
     # if we've reached this point and we did fork,
     # then we're the child process and we should stop now