* Switch to packaging

* install package

* fix

* support isolated builds

…340)

* workflows: add a workflow_dispatch trigger to start workflows manually

To be able to manually run a workflow from the Github web interface, add
a workflow_dispatch trigger.

Note that this does only work once this change has hit the default
branch.

* workflow: remove python 2.7 testing

Python 2.7 is long obsolete, deprecated and not supported any more.
Remove it from the tests. This test job is especially supposed to run on
ubuntu-20.04, which doesn't have Python 2.7 any more.

Without this patch, this workflow fails with:

  Warning: The support for python 2.7 will be removed on June 19. Related issue: actions/setup-python#672
  Version 2.7 was not found in the local cache
  Error: The version '2.7' with architecture 'x64' was not found for Ubuntu 20.04.
  The list of all available versions can be found here: https://raw.githubusercontent.com/actions/python-versions/main/versions-manifest.json

* setup.py: ignore flake8 warning about module import at top of file

Flake8 is unhappy with us because we violate PEP8:

rsc@leda:~/git/nodeenv$ flake8 --extend-ignore=E127 nodeenv.py tests setup.py
setup.py:16:1: E402 module level import not at top of file

Ignore this warning in this case.

* nodeenv.py: do not compare types

According to this flake8 error:

(env) rsc@leda:~/git/nodeenv$ flake8 --extend-ignore=E127 nodeenv.py tests setup.py
nodeenv.py:421:19: E721 do not compare types, for exact checks use `is` / `is not`, for instance checks use `isinstance()`

we should not compare types but use isinstance() instead, which can
handle subclasses as well.

See https://www.flake8rules.com/rules/E721.html for details.

* workflows: add test coverage for Python 3.12

Python 3.12 has been released for a while, add test coverage support in
our workflows.

* tox: add environment for Python 3.11

Create a Python 3.11 test environment.

* tox: add environment for Python 3.12

Create a Python 3.12 test environment.

…tion (#352)

* On Python 3.3+, replace pipes.quote with shlex.quote

The pipes.quote() function was undocumented, and the pipes module was
deprecated in Python 3.11 and will be removed in Python 3.13.

Fixes #341.

* Choose shlex or pipes based on Python version

It was pointed out that pyupgrade can handle this better than
try/except.

* fix tests after #342

* add coverage files into gitignore

* Use Python's shutil.which() instead of shelling out to `which` to find Python 2
* Use `command -v` instead of `which` in README

Fixes: #333