I am trying to build the latest Hadoop-trunk branch for development. To build the distribution I am using the mvn clean install -DskipTests command followed by mvn package -Pdist,native,docs -DskipTests -Dtar The maven build passes but I face the following error when trying to run hdfs namenode -format : Error: A JNI error has occurred, please check your installation and try again Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/hadoop/hdfs/protocol/ClientProtocol at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:763) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) at java.net.URLClassLoader.access$100(URLClassLoader.java:73) at java.net.URLClassLoader$1.run(URLClassLoader.java:368) at java.net.URLClassLoader$1.run(URLClassLoader.java:362) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:361) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2701) at java.lang.Class.privateGetMethodRecursive(Class.java:3048) at java.lang.Class.getMethod0(Class.java:3018) at java.lang.Class.getMethod(Class.java:1784) at sun.launcher.LauncherHelper.validateMainClass(LauncherHelper.java:544) at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:526) Caused by: java.lang.ClassNotFoundException: org.apache.hadoop.hdfs.protocol.ClientProtocol at java.net.URLClassLoader.findClass(URLClassLoader.java:381) at java.lang.ClassLoader.loadClass(ClassLoader.java:424) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349) at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ... 19 more I am using a Ubuntu-Xenial vagrant system. The following is the class path which is generated when --debug option is used : CLASSPATH: /vagrant/hadoop-trunk/hadoop-common-project/hadoop-common/target/hadoop-common-3.2.0-SNAPSHOT/etc/hadoop:/vagrant/hadoop-trunk/hadoop-common-project/hadoop-common/target/hadoop-common-3.2.0-SNAPSHOT/share/hadoop/common/lib/*:/vagrant/hadoop-trunk/hadoop-common-project/hadoop-common/target/hadoop-common-3.2.0-SNAPSHOT/share/hadoop/common/*:/vagrant/hadoop-trunk/hadoop-hdfs-project/hadoop-hdfs/target/hadoop-hdfs-3.2.0-SNAPSHOT/share/hadoop/hdfs:/vagrant/hadoop-trunk/hadoop-hdfs-project/hadoop-hdfs/target/hadoop-hdfs-3.2.0-SNAPSHOT/share/hadoop/hdfs/lib/*:/vagrant/hadoop-trunk/hadoop-hdfs-project/hadoop-hdfs/target/hadoop-hdfs-3.2.0-SNAPSHOT/share/hadoop/hdfs/* and the HADOOP_OPTS HADOOP_OPTS: -Djava.net.preferIPv4Stack=true -Dhdfs.audit.logger=INFO,NullAppender -Dhadoop.security.logger=INFO,RFAS -Dyarn.log.dir=/vagrant/hadoop-trunk/hadoop-dist/target/hadoop-3.2.0-SNAPSHOT/logs -Dyarn.log.file=hadoop.log -Dyarn.home.dir=/vagrant/hadoop-trunk/ -Dyarn.root.logger=INFO,console -Djava.library.path=/vagrant/hadoop-trunk/hadoop-dist/target/hadoop-3.2.0-SNAPSHOT/lib/native -Dhadoop.log.dir=/vagrant/hadoop-trunk/hadoop-dist/target/hadoop-3.2.0-SNAPSHOT/logs -Dhadoop.log.file=hadoop.log -Dhadoop.home.dir=/vagrant/hadoop-trunk/hadoop-dist/target/hadoop-3.2.0-SNAPSHOT -Dhadoop.id.str=vagrant -Dhadoop.root.logger=INFO,console -Dhadoop.policy.file=hadoop-policy.xml How can I go about fixing this error? EDIT : Fixed ... View more