invoke example from docs

tasks.py

from invoke import task, run

@task
def clean():
    print("Cleaning")

@task('clean')
def build():
    print("Building")

@task(pre=['build'])
def package():
    print("Packaging")

So this is the code directly from the documentation. But the basic commands are not performing as expected (by me anyway).

http://docs.pyinvoke.org/en/latest/concepts/execution.html#task-deduplication