Hi All, 

I've started to see a strange error in a simple enough parallel computation. 

I can reproduce it with the script below but with some other scripts where the code is embedded it runs fine so it may be a race condition. 

from yt.mods import *

pf = load("/wrk/regan/H2/Ctrl/DD0035/Data0035")
v, c = pf.h.find_max("Density")
print v, c

Thanks in advance for any help!

Cheers,
John

Error:

Traceback (most recent call last):
P001 yt : [INFO     ] 2013-12-29 09:31:27,756 Max Value is 3.67832e-16 at 0.5025423020124483 0.4896353334188484 0.4947452098131160 in grid EnzoGrid_1214 at level 18 (3, 3, 2)
Traceback (most recent call last):
  File "ptest.py", line 5, in <module>
P003 yt : [INFO     ] 2013-12-29 09:31:27,756 Max Value is 3.67832e-16 at 0.5025423020124483 0.4896353334188484 0.4947452098131160 in grid EnzoGrid_1214 at level 18 (3, 3, 2)
  File "ptest.py", line 5, in <module>
Traceback (most recent call last):
  File "ptest.py", line 5, in <module>
P002 yt : [INFO     ] 2013-12-29 09:31:27,756 Max Value is 3.67832e-16 at 0.5025423020124483 0.4896353334188484 0.4947452098131160 in grid EnzoGrid_1214 at level 18 (3, 3, 2)
Traceback (most recent call last):
P004 yt : [INFO     ] 2013-12-29 09:31:27,756 Max Value is 3.67832e-16 at 0.5025423020124483 0.4896353334188484 0.4947452098131160 in grid EnzoGrid_1214 at level 18 (3, 3, 2)
Traceback (most recent call last):
  File "ptest.py", line 5, in <module>
P005 yt : [INFO     ] 2013-12-29 09:31:27,756 Max Value is 3.67832e-16 at 0.5025423020124483 0.4896353334188484 0.4947452098131160 in grid EnzoGrid_1214 at level 18 (3, 3, 2)
Traceback (most recent call last):
  File "ptest.py", line 5, in <module>
P006 yt : [INFO     ] 2013-12-29 09:31:27,756 Max Value is 3.67832e-16 at 0.5025423020124483 0.4896353334188484 0.4947452098131160 in grid EnzoGrid_1214 at level 18 (3, 3, 2)
Traceback (most recent call last):
  File "ptest.py", line 5, in <module>
Traceback (most recent call last):
  File "ptest.py", line 5, in <module>
Traceback (most recent call last):
  File "ptest.py", line 5, in <module>
  File "ptest.py", line 5, in <module>
    v, c = pf.h.find_max("Density")
    v, c = pf.h.find_max("Density")
    v, c = pf.h.find_max("Density")
    v, c = pf.h.find_max("Density")
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 51, in find_max
    v, c = pf.h.find_max("Density")
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 51, in find_max
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 51, in find_max
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 51, in find_max
    v, c = pf.h.find_max("Density")
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 51, in find_max
    v, c = pf.h.find_max("Density")
    v, c = pf.h.find_max("Density")
    v, c = pf.h.find_max("Density")
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 51, in find_max
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 51, in find_max
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 51, in find_max
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 51, in find_max
    mg, mc, mv, pos = self.find_max_cell_location(field, finest_levels)
    mg, mc, mv, pos = self.find_max_cell_location(field, finest_levels)
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 66, in find_max_cell_location
    mg, mc, mv, pos = self.find_max_cell_location(field, finest_levels)
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 66, in find_max_cell_location
  File "/homeappl/home/regan/appl_taito/YT/yt-x86_64/src/yt-hg/yt/data_objects/object_finding_mixin.py", line 66, in find_max_cell_location
    mg, mc, mv, pos = self.find_max_cell_location(field, finest_levels)