List<String> command = new ArrayList<String>();
command.add(protocCommand);
command.add("--version");
Exec exec = new Exec(this);
List<String> out = new ArrayList<String>();
if (exec.run(command, out) == 127) {
getLog().error("protoc, not found at: " + protocCommand);
throw new MojoExecutionException("protoc failure");
} else {
if (out.isEmpty()) {
getLog().error("stdout: " + out);