I argue that a major part of becoming a contributor for Bigtop is a learning curve in how to use all the mechanics of the trade. I see this times and again.
We need to have a HOWTO.txt document that would have a trivial description of the needed steps. Something like:
clone Bigtop repo
mvn install top pom.xml
mvn install itest
set HADOOP_CONF_DIR, HADOOP_HOME, HADOOP_MAPRED_HOME
mvn install test-artifacts top pom.xml
mvn install test-execution top pom.xml
mvn -Dorg.apache.bigtop.itest.log4j.level=TRACE -f bigtop-tests/test-execution/smokes/hadoop/pom.xml verify
That might be sufficient.