Compilation error while instrumenting clover

Compilation error while instrumenting the amps code base with clover.

I tried with both maven.clover.useFullyQualifiedJavaLang true/false

Env : Mac + JDK 8
Repository : https://bitbucket.org/atlassian/amps
Command : mvn clean clover:setup verify clover2:aggregate clover2:clover -Dmaven.clover.useFullyQualifiedJavaLang=true

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.2:compile (default-compile) on project maven-amps-plugin: Compilation failure: Compilation failure:
[ERROR] /Users/nraman/Development/amps/maven-amps-plugin/target/clover/src-instrumented/com/atlassian/maven/plugins/amps/util/ant/AntJavaExecutorThread.java:[34,703] non-static variable java cannot be referenced from a static context
[ERROR] /Users/nraman/Development/amps/maven-amps-plugin/target/clover/src-instrumented/com/atlassian/maven/plugins/amps/util/ant/AntJavaExecutorThread.java:[34,707] cannot find symbol
[ERROR] symbol:   variable lang
[ERROR] location: variable java of type org.apache.tools.ant.taskdefs.Java
[ERROR] /Users/nraman/Development/amps/maven-amps-plugin/target/clover/src-instrumented/com/atlassian/maven/plugins/amps/util/ant/AntJavaExecutorThread.java:[34,2237] non-static variable java cannot be referenced from a static context