Fix MPI build. (#6403)

tests/distributed/runtests-mpi.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+rm -f *.model*
+
+export DMLC_SUBMIT_CLUSTER=mpi
+
+submit="timeout 5 python ../../dmlc-core/tracker/dmlc-submit"
+
+echo "====== 1. Basic distributed test with Python ======"
+$submit --cluster=local --num-workers=3 python test_basic.py
+
+echo "====== 2. Regression test for issue #3402 ======"
+$submit --cluster=local --num-workers=2 --worker-cores=1 python test_issue3402.py

tests/distributed/test_issue3402.py

@@ -65,7 +65,7 @@ y = [1, 0]
 
 dtrain = xgb.DMatrix(X, label=y)
 
-param = {'max_depth': 2, 'eta': 1, 'silent': 1, 'objective': 'binary:logistic' }
+param = {'max_depth': 2, 'eta': 1, 'objective': 'binary:logistic' }
 watchlist  = [(dtrain,'train')]
 num_round = 2
 bst = xgb.train(param, dtrain, num_round, watchlist)