Intermittant eckit_test_mpi_parallel failures

[DJDavies2]

I am getting intermittant failures in eckit_test_mpi_parallel with this sort of output:

Running case 19: test_probe ...
Completed case 18: test_waitAny
Running case 19: test_probe ...
Completed case 18: test_waitAny
Running case 19: test_probe ...
Completed case 18: test_waitAny
Running case 19: test_probe ...
Completed case 19: test_probe
Running case 20: test_iProbe ...
Completed case 19: test_probe
Running case 20: test_iProbe ...
Completed case 19: test_probe
Running case 20: test_iProbe ...
�[31mTest "test_probe" failed: Condition failed: i == data[i] @ (/home/d03/frwd/cylc-run/EckitFailures/share/mo-bundle/eckit/tests/mpi/eckit_test_mpi.cc +776 test_746)�[0m
Completed case 19: test_probe
Running case 20: test_iProbe ...
Completed case 20: test_iProbe
0 tests failed out of 21.
Completed case 20: test_iProbe
0 tests failed out of 21.
Completed case 20: test_iProbe
0 tests failed out of 21.
�[31mTest "test_iProbe" failed: Condition failed: i == data[i] @ (/home/d03/frwd/cylc-run/EckitFailures/share/mo-bundle/eckit/tests/mpi/eckit_test_mpi.cc +821 test_786)�[0m
Completed case 20: test_iProbe
FAILED: test_probe
FAILED: test_iProbe
2 tests failed out of 21.

The output varies slightly when it fails but it is in the test_probe/test_iProbe tests. The platform where this fails is a Cray using either gcc 6.3.0 or Intel 2018.