StopIteration: (virtualenv/run/plugin/discovery.py:22) with 0.13.0

[arcivanov]

$ pyb -vX
[DEBUG] Registered Python environment 'system': CPython version 3.9.7.final.0 on linux in ['/home/username/.pyenv/versions/3.9.7/envs/project/bin/python3.9']
PyBuilder version 0.13.0.dev20210912232320
Build started at 2021-09-15 01:31:58
------------------------------------------------------------
[DEBUG] Loading project module from ./build.py
[DEBUG] Setting up plugins VEnv at '/home/username/Documents/src/karellen/project/.pybuilder/plugins/cpython-3.9.7.final.0'
Traceback (most recent call last):
  File "/home/username/.pyenv/versions/3.9.7/envs/project/lib/python3.9/site-packages/pybuilder/cli.py", line 461, in main
    reactor.prepare_build(property_overrides=options.property_overrides,
  File "/home/username/.pyenv/versions/3.9.7/envs/project/lib/python3.9/site-packages/pybuilder/reactor.py", line 203, in prepare_build
    self._setup_plugin_directory(reset_plugins, no_venvs)
  File "/home/username/.pyenv/versions/3.9.7/envs/project/lib/python3.9/site-packages/pybuilder/reactor.py", line 512, in _setup_plugin_directory
    plugin_env = per["pybuilder"] = PythonEnv(plugin_dir, self).create_venv(with_pip=True,
  File "/home/username/.pyenv/versions/3.9.7/envs/project/lib/python3.9/site-packages/pybuilder/python_env.py", line 214, in create_venv
    create_venv(self._env_dir,
  File "/home/username/.pyenv/versions/3.9.7/envs/project/lib/python3.9/site-packages/pybuilder/python_env.py", line 419, in create_venv
    virtualenv.cli_run(args, setup_logging=False)
  File "/home/username/.pyenv/versions/3.9.7/envs/project/lib/python3.9/site-packages/pybuilder/_vendor/virtualenv/run/__init__.py", line 30, in cli_run
    of_session = session_via_cli(args, options, setup_logging, env)
  File "/home/username/.pyenv/versions/3.9.7/envs/project/lib/python3.9/site-packages/pybuilder/_vendor/virtualenv/run/__init__.py", line 48, in session_via_cli
    parser, elements = build_parser(args, options, setup_logging, env)
  File "/home/username/.pyenv/versions/3.9.7/envs/project/lib/python3.9/site-packages/pybuilder/_vendor/virtualenv/run/__init__.py", line 69, in build_parser
    discover = get_discover(parser, args)
  File "/home/username/.pyenv/versions/3.9.7/envs/project/lib/python3.9/site-packages/pybuilder/_vendor/virtualenv/run/plugin/discovery.py", line 22, in get_discover
    default=next(iter(choices)),
StopIteration
------------------------------------------------------------
BUILD FAILED - StopIteration:  (virtualenv/run/plugin/discovery.py:22)
------------------------------------------------------------
Build finished at 2021-09-15 01:31:58
Build took 0 seconds (59 ms)

[arcivanov]

Related to #771, #774 and #777