M2 module builds seem to always fail under 1.87 with an exception like this one:

started
[] $ /System/Library/Frameworks/JavaVM.framework/Versions/1.5.0/Home/bin/java
-cp
/opt/tomcat-hudson/webapps/hudson/WEB-INF/lib/maven-agent-1.87.jar:/opt/maven/core/boot/classworlds-1.1.jar
hudson.maven.agent.Main /opt/maven
/opt/tomcat-hudson/webapps/hudson/WEB-INF/lib/hudson-core-1.87.jar
/opt/tomcat-hudson/webapps/hudson/WEB-INF/lib/maven-interceptor-1.87.jar
channel started
FATAL: null
java.lang.NullPointerException
at hudson.maven.agent.Main.launch(Main.java:65)
at hudson.maven.MavenBuild$Builder.call(MavenBuild.java:127)
at hudson.maven.MavenBuild$Builder.call(MavenBuild.java:105)
at hudson.remoting.UserRequest.perform(UserRequest.java:57)
at hudson.remoting.UserRequest.perform(UserRequest.java:22)
at hudson.remoting.Request$2.run(Request.java:178)
at
edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:665)
at
edu.emory.mathcs.backport.java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:690)
at java.lang.Thread.run(Thread.java:613)

This did not happen in 1.85. See also:
https://hudson.dev.java.net/servlets/ReadMsg?list=users&msgNo=1119 .