$cat maven.sh
export MAVEN_OPTS="-Dlog4j.configuration=file:./log4j.properties"
sh -x $MAVEN_HOME/bin/maven
:$cat log4j.properties
# ------------------------------------------------------------------------
# This is the log4j configuration file that is distributed with Maven.
# ------------------------------------------------------------------------
log4j.appender.console=org.apache.log4j.ConsoleAppender
log4j.appender.console.layout=org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=%m%n
log4j.rootCategory = debug , console
#log4j.category=debug
log4j.category.org.apache.maven=debug
#log4j.category.org.apache.commons=debug
