Argument parser gets confused with values starting with a dash

[kasium]

If the following task gets called as followed, I get an error

@task
def exec(context, args):
    print(args)

inv exec --args="-a" -> Flag <Argument: args (a) *> needed value and was not given one!

However, the following are working:

• inv exec --args "-a 1"
• inv exec --args "--a"

[kasium]

Seems to be resoled with invoke 2.x