org.apache.maven.plugin.MojoExecutionException: protoc failure
The instructions at http://wiki.apache.org/hadoop/HowToContribute explain some of the less obvious aspects of building hadoop - including this one. The main problem here is that Protocol Buffers are required by hadoop's YARN framework, and you most likely do not have them installed.
It seems like the problem might be that your not interpretting the error correctly, so --
How to Isolate the Build error
Any mojo which fails should be associated with a class.
In this case, the mojo that is failing is here :
Looking at the code, its clear that this Mojo requires the "protoc" program to run.
http://code.google.com/p/protobuf/
Solution
To build hadoop, you need protocol buffers. This can be installed on a *NIX machine from source, by running the following commands to grab the code from googlecode (taken from http://numbers.brighterplanet.com/2012/04/14/how-to-install-mosh-on-amazon-ec2/).
wget http://protobuf.googlecode.com/files/protobuf-2.4.1.tar.gztar xzf protobuf-2.4.1.tar.gzcd protobuf-2.4.1./configuremakesudo make installsudo ldconfig