This test actually performs better with random values - when every node takes the same amount of time to return, there's a much more likely chance of all of them returning at the same moment, and thus overshooting the mutex requirement for unblocking.

tests/integration/learning/test_discovery_phases.py

@@ -190,7 +190,7 @@ def test_mass_treasure_map_placement(fleet_of_highperf_mocked_ursulas,
 
         # The number of nodes having the map is approximately the number you'd expect from full utilization of Alice's publication threadpool.
         # TODO: This line fails sometimes because the loop goes too fast.
-        # assert nodes_that_have_the_map_when_we_unblock == pytest.approx(policy.publishing_mutex._threadpool.max, .6)
+        assert nodes_that_have_the_map_when_we_unblock == pytest.approx(policy.publishing_mutex._threadpool.max, .6)
 
         # Temporarily: *some* nodes have it.
         assert nodes_that_have_the_map_when_we_unblock

tests/utils/middleware.py

@@ -15,6 +15,7 @@ You should have received a copy of the GNU Affero General Public License
 along with nucypher.  If not, see <https://www.gnu.org/licenses/>.
 """
 import time
+import random
 
 import requests
 import socket
@@ -133,9 +134,9 @@ class SluggishLargeFleetMiddleware(MockRestMiddlewareForLargeFleetTests):
     Similar to above, but with added delay to simulate network latency.
     """
     def put_treasure_map_on_node(self, node, *args, **kwargs):
-        time.sleep(.1)
+        time.sleep(random.randrange(5, 15) / 100)
         result = super().put_treasure_map_on_node(node=node, *args, **kwargs)
-        time.sleep(.1)
+        time.sleep(random.randrange(5, 15) / 100)
         return result