If there is a pid recorded for the prerender, but the process is dead, just print a warning and continue (don't die)
If there is a pid recorded for the prerender, but the process is dead,
just print a warning and continue (don't die)

nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome,nmc-probe/emulab-nome