SPARK-1658: Correctly identify if maven is installed and working

The current test is checking the exit code of "tail" rather than "mvn".
This new check will make sure that mvn is installed and was able to
execute the "version command".

Author: Rahul Singhal

make-distribution.sh

@@ -43,12 +43,13 @@
 FWDIR="$(cd `dirname $0`; pwd)"
 DISTDIR="$FWDIR/dist"
 
-VERSION=$(mvn help:evaluate -Dexpression=project.version | grep -v "INFO" | tail -n 1)
-if [ $? == -1 ] ;then
+VERSION_TEXT=$(mvn help:evaluate -Dexpression=project.version 2>/dev/null)
+if [ $? != 0 ] ;then
     echo -e "You need Maven installed to build Spark."
     echo -e "Download Maven from https://maven.apache.org."
     exit -1;
 fi
+VERSION=$(echo "$VERSION_TEXT" | grep -v "INFO" | tail -n 1)
 
 # Initialize defaults
 SPARK_HADOOP_VERSION=1.0.4