Why won't eclipse switch the compiler to Java 8?

Question

I checked out a Java project from SVN in eclipse and realized that it requires Java 8 because it uses lambdas etc. I installed the eclipse addon for Java 8 and restarted ecl

Answer 1

        
            
                org.apache.maven.plugins
                maven-compiler-plugin
                3.6.1
                
                    1.8
                    1.8