Can't use python3 typing for tasks

[sprat]

I would like to use python3 typing on my tasks, e.g.:

@task
def hostname(c, hostname: str):
    """Define the hostname"""
    print(f'Setting hostname: {hostname}')
    c.sudo(f'hostnamectl set-hostname {hostname}')

However, it fails with the following error:

Traceback (most recent call last):
  File "/home/sylvain/.virtualenvs/fabric-nas/bin/fab", line 8, in <module>
    sys.exit(program.run())
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/invoke/program.py", line 373, in run
    self.parse_collection()
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/invoke/program.py", line 465, in parse_collection
    self.load_collection()
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/fabric/main.py", line 87, in load_collection
    super(Fab, self).load_collection()
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/invoke/program.py", line 696, in load_collection
    module, parent = loader.load(coll_name)
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/invoke/loader.py", line 76, in load
    module = imp.load_module(name, fd, path, desc)
  File "/usr/lib/python3.8/imp.py", line 234, in load_module
    return load_source(name, filename, file)
  File "/usr/lib/python3.8/imp.py", line 171, in load_source
    module = _load(spec)
  File "<frozen importlib._bootstrap>", line 702, in _load
  File "<frozen importlib._bootstrap>", line 671, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 783, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/home/sylvain/Dev/fabric-nas/fabfile.py", line 2, in <module>
    from lib import system
  File "/home/sylvain/Dev/fabric-nas/lib/system.py", line 5, in <module>
    def hostname(c, hostname: str):
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/fabric/tasks.py", line 71, in task
    return invoke.task(*args, **kwargs)
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/invoke/tasks.py", line 325, in task
    return klass(args[0], **kwargs)
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/fabric/tasks.py", line 21, in __init__
    super(Task, self).__init__(*args, **kwargs)
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/invoke/tasks.py", line 76, in __init__
    self.positional = self.fill_implicit_positionals(positional)
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/invoke/tasks.py", line 167, in fill_implicit_positionals
    args, spec_dict = self.argspec(self.body)
  File "/home/sylvain/.virtualenvs/fabric-nas/lib/python3.8/site-packages/invoke/tasks.py", line 153, in argspec
    spec = inspect.getargspec(func)
  File "/usr/lib/python3.8/inspect.py", line 1083, in getargspec
    raise ValueError("Function has keyword-only parameters or annotations"
ValueError: Function has keyword-only parameters or annotations, use inspect.signature() API which can support them

Can typing be supported in invoke?

[wawamanhunt]

there seem to be a few PRs to fix this problem but unsure when any will be merged, one of these PRs #458 has a few workarounds to this in the comments

[sprat]

Thanks for the information, I guess it won't be fixed anytime soon.

[bitprophet]

2.0.0 will be out soon & is now using inspect.signature!