[molecule.utils] remove RUNNING_PIDS set

This ill conceived idea of killing stale chroot child processes does more
harm than good and the idea has been inherited long time ago from the Catalyst
codebase. Chroot processes are responsible of their cleanup.

molecule.py

@@ -25,11 +25,6 @@ sys.path.insert(0,'molecule/')
 sys.path.insert(0,'.')
 import molecule.cmdline
 from molecule.handlers import Runner
-from molecule.utils import RUNNING_PIDS
-
-def kill_pids():
-    for pid in RUNNING_PIDS:
-        os.kill(pid, signal.SIGTERM)
 
 parse_data = molecule.cmdline.parse()
 if parse_data is None:
@@ -46,12 +41,10 @@ for el in molecule_data_order:
     except KeyboardInterrupt:
         while True:
             my.kill()
-            kill_pids()
             break
         raise SystemExit(1)
     while True:
         my.kill()
-        kill_pids()
         break
     if rc != 0:
         raise SystemExit(rc)

molecule/utils.py

@@ -31,8 +31,6 @@ random.seed()
 
 from molecule.compat import convert_to_rawstring
 
-RUNNING_PIDS = set()
-
 
 def get_year():
     """
@@ -153,9 +151,7 @@ def exec_chroot_cmd(args, chroot, pre_chroot = None, env = None):
         myargs = pre_chroot+args
         os.execvp(myargs[0], myargs)
     else:
-        RUNNING_PIDS.add(pid)
         rcpid, rc = os.waitpid(pid, 0)
-        RUNNING_PIDS.discard(pid)
         return rc
 
 def kill_chroot_pids(chroot, sig = signal.SIGTERM, sleep = False):