Cannot rename root_hist_prune to root_hist?

Hi everyone, I am running a large number of jobs on a cluster using the same compiled ROOT macro. Out of something like ~2000 jobs, ONE of them gave this error in the stderr log file:

Is this a concurrency issue with the ROOT history? Should I be concerned? How can I prevent this ERROR from occuring?

Also note that the error message didn’t have a newline at the end, so I think that the last “Info in <TCanvas…” part is a separate regular TObject::Info message.