Why isn't a custom task failing to execute in lineman build but works with lineman grunt <task name>?

[ghost]

Task in the task folder:

module.exports = function(grunt) {
    return grunt.registerTask('dl-hello-world', 'DLABS Hello World', function(){
        grunt.log.writeln("Hello from DLABS");
    });
};

application.js configuration:

       // omitted other config elements for brevity sake
        prependTasks: {
            common: ["dl-hello-world'"]
        }

Results when I run lineman grunt dl-hello_world

$ lineman grunt dl-hello-world
Running "dl-hello-world" task
Hello from DLABS

Done, without errors.

Results when I run lineman build

$ lineman build
Running "clean:dist" (clean) task

Running "common" task
Warning: Task "dl-hello-world'" not found. Use --force to continue.

Aborted due to warnings.

[ghost]

It is the a bug on my code ... a spelling error, and extra ' in the dl-hello-world task name.

My apologies for writing a useless bug.