code: static function run_check_gnu_files( $task=null, $args=array(), $cliopts=array() )
      {
          $opts = self::getOpts( @$args[0], @$args[1], $cliopts );
          if ( !SharedLock::acquire( $opts['extension']['name'], LOCK_SH, $opts ) )
              throw new PakeException( "Source code locked by another process" );
  
          $destdir = self::getBuildDir( $opts ) . '/' . $opts['extension']['name'];
          if ( $opts['files']['gnu_dir'] )
          {
              $destdir .= '/' . $opts['files']['gnu_dir'];
          }
          $files = pakeFinder::type( 'file' )->name( array( 'README', 'LICENSE' ) )->maxdepth( 0 )->in( $destdir );
          if ( count( $files ) != 2 )
          {
              SharedLock::release( $opts['extension']['name'], LOCK_SH, $opts );
              throw new pakeException( "README and/or LICENSE files missing. Please fix" );
          }
  
          SharedLock::release( $opts['extension']['name'], LOCK_SH, $opts );
      }
docs: Checks for presence of files README and LICENSE, by default in extension root
  directory - but a config parameter is allowed to specify their location