blast: minor cleanups

hosts/common/programs/blast-ugjka/blast-to-default

@@ -30,8 +30,10 @@ def set_pdeathsig(sig=signal.SIGTERM):
 
 MY_PID = None
 
-def reap_children(*args, **kwargs):
+def reap_children(sig=None, frame=None):
     global MY_PID
+    # reset SIGTERM handler to avoid recursing
+    signal.signal(signal.SIGTERM, signal.Handlers.SIG_DFL)
     logger.info("killing all children (of pid %d)", MY_PID)
     os.killpg(MY_PID, signal.SIGTERM)
 
@@ -94,8 +96,8 @@ class BlastDriver:
             stdin=subprocess.PIPE,
             stdout=subprocess.PIPE,
             stderr=subprocess.PIPE,
-            # TODO: is this pdeathsig necessary? probably not.
-            preexec_fn=set_pdeathsig
+            # this pdeathsig isn't necessary; seems it might result in leaked pulse outputs
+            # preexec_fn=set_pdeathsig
         )
         self.blast_flags = list(blast_flags)
         self.receiver_names = []