Having the following buildout.cfg:

[buildout]
extensions = mr.developer
sources-dir = dep
auto-checkout = *
parts = scripts
develop = .
versions = versions

[versions]
zc.buildout = 2.2.0

#  jedi and epc are eggs needed for jedi.  Folded into the scripts
#  part in order to reduce the number of parts that take time.
[scripts]
recipe = zc.recipe.egg
eggs = jedi
       epc
       RBTools

interpreter = python

results in:

bin/buildout
While:
  Installing.
  Loading extensions.
Error: There is a version conflict.
We already have: zc.buildout 2.2.3

The current zc.buildout version is 2.2.3, that gets downloaded by bootstrap.py The problem can be fixed by either python bootstrap.py --version=2.2.0 or nailing zc.buildout = 2.2.3

Currently, buildout cannot install wheels. There are several issues about that, like #316. I have been wanting to experiment with getting this to work. So I went hacking. See the pip branch in my fork and compare.

This is very far from complete. I was just curious on how far I could come with a couple of hours work. Maybe others can continue in this direction, or we can conclude that this way is not viable.

So how do you use this for testing:

• Create a virtualenv (I used Python 2.7 on Mac) and activate it.
• git clone my branch
• Go to the zc.buildout clone and do python setup.py develop.
• Go to the zc.recipe.egg_ sub directory and do python setup.py develop.
• Return to the main virtualenv directory.
• Create a buildout.cfg to your liking and run buildout.
• Run buildout a couple of times to get past some problems.

The buildout.cfg I used, was this:

[buildout]
parts = test command backup
# Possibly add develop lines like this:
# develop =
#     /Users/maurits/community/buildout/
#     /Users/maurits/community/buildout/zc.recipe.egg_

[test]
recipe = zc.recipe.egg
eggs = zest.releaser

[command]
recipe = plone.recipe.command
command = echo Running command recipe.
update-command = ${:command}

[backup]
recipe = collective.recipe.backup
backup_blobs = false

[versions]
# Latest zest.releaser is 6.8, pin an earlier one.
zest.releaser = 6.7
plone.recipe.command = 1.1

It has three parts, to show three different recipes that basically work.

• zc.recipe.egg installs an egg plus its dependencies, including scripts. The bin/release script works, quitting with an expected error (there is nothing to release here).
• plone.recipe.command performs a command during buildout run.
• collective.recipe.backup creates some scripts for backing up a Zope/Plone database. The bin/backup script works, quitting with an expected error (there is no database here).

Some remarks:

• You must be in a virtualenv, and the current working directory must be the root of the virtualenv. Buildout will quit with an error if this is not the case. This is just to avoid my code messing up your system. You still use it at your own risk.
• The code does not shell out to pip on a command line.
• The code imports all kinds of stuff from pip. This may not be stable at all. I am not aware of an api for pip. If we want to go this way, we should ask for such an api, and help create and test it.
• There are lots of buildout options that we could in some way pass to pip, but currently I don't. At this moment I don't care if newest=true/false works, or if we can use an alternative index.
• There are lots of pip options that I am currently not using.
• Various things are hardcoded.
• You may need to run buildout a couple of times: after installing a recipe, buildout wants to import the recipe, which at first fails.
• I changed stuff in zc.buildout and in the included zc.recipe.egg_. Most importantly, in easy_install.install I am no longer creating an easy_install.Installer, but I use the new install function inzcpip.py.
• In zcpip.py I am basically trying to do what pip.commands.install.InstallCommand.run does, and have ripped out as much as I could, to keep things a bit simpler.
• Drawback of this approach with installing everything in a virtualenv: all scripts will have the same packages installed. So you cannot install a script bin/script-with-package-X and a script bin/script-without-package-X to check if your code works properly both with and without an optional dependency.

Closing remarks:

• No this is not ready. Do not use this in production.
• Yes, it is ugly and has problems.
• Hey, some stuff works! :-)

http://pypi.python.org/pypi/zc.recipe.egg/1.3.2#script-generation does not work.

You can verify this with the following test package: http://pypi.python.org/pypi/tompoes/0.0.2.

It seems zc.buildout.easy_install isn't doing it's work properly.

There is one more issue, which might or might not be related. In any case, the example package has only 1 module; tompoes.py. This module is NOT installed. That means the endpoint tom isn't working!

Since I've got no idea if this bug is caused by the failure to install scripts, I added it to this ticket instead of creating a separate issue.

The last successful build was 2 months ago: https://travis-ci.org/buildout/buildout/builds/553658470

Today I merged a typo fix in a doctest and the build is failing: https://travis-ci.org/buildout/buildout/builds/574320041

The Python 2.7 build fails three tests, all Python 3.x builds hang.

setuptools 34.0.0 just introduced 3 new deps and deprecated the ez_setup.py (pinned to 33.1.1). I am not sure if bootstrap.py can be updated to reflect the setuptools upgrade.

Carlos

Hi,

I have the following buildout.cfg

[buildout]
include-site-packages = false
versions = versions

parts =
    makedirs

eggs =
    six

[versions]
six = 1.10.0

[makedirs]
recipe = z3c.recipe.mkdir
paths = ${buildout:directory}/var

When I call bin/buildout I expect to see six in the eggs folder at the end but buildout doesn't do it.

What is wrong with this, how to force buildout to put egg into eggs folder?

I tried to add custom egg definition and include it in parts but it didn't work too.

Thanks.

Default to setuptools' wheel support instead of failing

Setuptools 38.2.0 suddenly started supporting and downloading wheels. .whl files would end up in the non-functioning and deprecated unpack_wheel(). The new default ('just use setuptools') works fine.

• If you use an older setuptools, setuptools won't download wheels and the new code won't be used.

• If you use buildout.wheel, you'll overwrite the unpacker anyway.

Fixes #425

This PR is meant to address the problem discussed here: https://community.plone.org/t/multiple-zope-instances-slow-buildout

Review is much appreciated because I'm new to buildout development (I'm a buildout heavy user, though).

Refer to pypa/setuptools/pull/1830.

Buildout still calling out to setuptools.command.easy_install in zc/buildout/easy_install.py:call_easy_install(spec, dest).

So what our take and future direction on this?

42.0.0 changelog also mentioned about eggs are not supported anymore.

#1830, #1909: Mark the easy_install script and setuptools command as deprecated, and use pip when available to fetch/build wheels for missing setup_requires/tests_require requirements, with the following differences in behavior:

    support for python_requires
    better support for wheels (proper handling of priority with respect to PEP 425 tags)
    PEP 517/518 support
    eggs are not supported

buildout.dumppickedversions has the option overwrite-picked-versions-file to overwrite instead of appending to the versions file. (https://github.com/collective/buildout.dumppickedversions/blob/master/src/buildout/dumppickedversions/init.py#L63)

Buildout 2.0 only provides update-versions-file. When using this option the picked versions file just grows each buildout run.

@reinout Do you think it's possible to add this behavior to buildout 2.0?

The latest changes in version 2.4.1 will break downloading a config file from a private pypi server.

bin/buildout -c https://user:[email protected]/myconfig.cfg

will end in:

  An internal error occurred due to a bug in either zc.buildout or in a recipe being used:
  Traceback (most recent call last):
    File "/xeebo/python27/lib/python2.7/site-packages/zc.buildout-2.4.1-py2.7.egg/zc/buildout/buildout.py", line 1986, in main
      user_defaults, command, args)
    File "/xeebo/python27/lib/python2.7/site-packages/zc.buildout-2.4.1-py2.7.egg/zc/buildout/buildout.py", line 231, in __init__
      data['buildout'].copy(), override, set()))
    File "/xeebo/python27/lib/python2.7/site-packages/zc.buildout-2.4.1-py2.7.egg/zc/buildout/buildout.py", line 1574, in _open
      path, is_temp = download(filename)
    File "/xeebo/python27/lib/python2.7/site-packages/zc.buildout-2.4.1-py2.7.egg/zc/buildout/download.py", line 117, in __call__
      local_path, is_temp = self.download(url, md5sum, path)
    File "/xeebo/python27/lib/python2.7/site-packages/zc.buildout-2.4.1-py2.7.egg/zc/buildout/download.py", line 196, in download
      tmp_path, headers = urlretrieve(url, tmp_path)
    File "/xeebo/python27/lib/python2.7/site-packages/zc.buildout-2.4.1-py2.7.egg/zc/buildout/download.py", line 41, in urlretrieve
      url_obj = urllib2.urlopen(url)
    File "/xeebo/python27/lib/python2.7/urllib2.py", line 127, in urlopen
      return _opener.open(url, data, timeout)
    File "/xeebo/python27/lib/python2.7/urllib2.py", line 404, in open
      response = self._open(req, data)
    File "/xeebo/python27/lib/python2.7/urllib2.py", line 422, in _open
      '_open', req)
    File "/xeebo/python27/lib/python2.7/urllib2.py", line 382, in _call_chain
      result = func(*args)
    File "/xeebo/python27/lib/python2.7/urllib2.py", line 1222, in https_open
      return self.do_open(httplib.HTTPSConnection, req)
    File "/xeebo/python27/lib/python2.7/urllib2.py", line 1153, in do_open
      h = http_class(host, timeout=req.timeout) # will parse host:port
    File "/xeebo/python27/lib/python2.7/httplib.py", line 1186, in __init__
      source_address)
    File "/xeebo/python27/lib/python2.7/httplib.py", line 706, in __init__
      (self.host, self.port) = self._get_hostport(host, port)
    File "/xeebo/python27/lib/python2.7/httplib.py", line 748, in _get_hostport
      raise InvalidURL("nonnumeric port: '%s'" % host[i+1:])
  InvalidURL: nonnumeric port: '[email protected]'

I have started using buildout 3.0.0.rc3 and noticed that it was not able to pull packages from a private pypi server with basic authentication.

This is the snippet that used to work in the past:

[some_package]
recipe = zc.recipe.egg
index =
    https://user:[email protected]/packages/simple
eggs = some_package

Now with 3.0.0rc3, it shows an error that has the following form:

While:
  Installing apps.
  Getting distribution for 'some_package'.
Error: Can't download https://pypi.example.com/api/packages/pypi/files/ml-demo/0.0.1/some_package-0.0.1.tar.gz#sha256-dda0a65e388a005f56c0d7d13c5737338b527dfdeafe3727f288441be857ed93: 401 Unauthorized

What this seems to say is that buildout can pull the index, which is also behind basic auth, but cannot pull the package itself, this is to say, the credentials are not used when downloading the package.

Dear @goschtl, @mauritsvanrees, @gotcha, and the whole Buildout community,

first things first: Thanks a stack for conceiving and maintaining this excellent package.

TLDR;

There is a minimal reproduction case repository at test-buildout-python310, where https://github.com/crate-workbench/test-buildout-python310/issues/1 swiftly outlines the problem.

Details

While working on https://github.com/crate/crate-python/pull/428, we ran into a similar problem you have been discussing at #606. We are also installing SQLAlchemy within a Buildout environment and it croaks specifically on Python 3.10 with macOS >= 11. Both Buildout 2 and Buildout 3 show the same symptom.

First, we thought it would be a problem with GHA, but then a colleague also confirmed the flaw happens on his workstation running macOS 12. On our research about this issue, we also discovered https://github.com/pypa/setuptools/issues/2514 by @idgserpro, where similar symptoms showed up.

In order to assist you with further research on this matter, we wrapped all up into a repository with a minimal reproduction case at test-buildout-python310, where the CI/GHA jobs will precisely highlight the build matrix items where the front falls off. https://github.com/crate-workbench/test-buildout-python310/issues/1 has more details about its outcome.

With kind regards, Andreas.

/cc @proddata

Screenshot

TLDR;

No eggs found in /var/folders/24/8k48jl6d249_n_qfxwsl6xvm0000gn/T/easy_install-uvggdcg2/zope.interface-5.2.0/egg-dist-tmp-s7mlm8qo (setup script problem?)

  File "/Users/runner/hostedtoolcache/Python/3.10.5/x64/lib/python3.10/site-packages/zc/buildout/easy_install.py", line 1745, in _move_to_eggs_dir_and_compile
    [tmp_loc] = glob.glob(os.path.join(tmp_dest, '*'))
ValueError: not enough values to unpack (expected 1, got 0)

Getting distribution for 'greenlet!=0.4.17'.
[...]
gcc: error: sh -c '/Applications/Xcode_13.2.1.app/Contents/Developer/usr/bin/xcodebuild -sdk /Applications/Xcode_13.2.1.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk -find gcc 2> /dev/null' failed with exit code 256: (null) (errno=Invalid argument)
xcode-select: Failed to locate 'gcc', requesting installation of command line developer tools.
error: Setup script exited with error: command '/usr/bin/gcc' failed with exit code 72

Hi @gotcha

here is an error I get when using zc.buildout 3.0.0rc3 while trying to install collective.jsonmigrator

So the problem is either in https://github.com/collective/collective.jsonmigrator/blob/master/setup.py where python_requires="==2.7, >=3.7" or in the way it is managed by zc.buildout?

Another thing is that the error message appears when asking for a fixed version, but if you do not pin a version, you have following message:

Getting distribution for 'transmogrify.dexterity==2.0.0'.
While:
  Installing instance1.
  Getting distribution for 'transmogrify.dexterity==2.0.0'.
Error: Couldn't find a distribution for 'transmogrify.dexterity==2.0.0'.

It would be great to have a message specifying that the version exists but is not python compatible.

See you! Gauthier

Hi,

i try to install sqlalchemy via zc.recipe.egg. Buildout3 rc3.

This is my config:

  4 [sqla]
  5 recipe = zc.recipe.egg
  6 eggs = sqlalchemy

I get this error on first run:

While:
  Installing sqla.
  Getting distribution for 'sqlalchemy'.

An internal error occurred due to a bug in either zc.buildout or in a
recipe being used:
Traceback (most recent call last):
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/buildout.py", line 2250, in main
    getattr(buildout, command)(args)
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/buildout.py", line 855, in install
    installed_files = self[part]._call(recipe.install)
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/buildout.py", line 1651, in _call
    return f()
  File "/Users/ck/.buildout/eggs/zc.recipe.egg-2.0.7-py3.8.egg/zc/recipe/egg/egg.py", line 227, in install
    reqs, ws = self.working_set()
  File "/Users/ck/.buildout/eggs/zc.recipe.egg-2.0.7-py3.8.egg/zc/recipe/egg/egg.py", line 78, in working_set
    ws = self._working_set(
  File "/Users/ck/.buildout/eggs/zc.recipe.egg-2.0.7-py3.8.egg/zc/recipe/egg/egg.py", line 161, in _working_set
    ws = zc.buildout.easy_install.install(
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/easy_install.py", line 971, in install
    return installer.install(specs, working_set)
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/easy_install.py", line 696, in install
    for dist in self._get_dist(requirement, ws):
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/easy_install.py", line 581, in _get_dist
    dists = [_move_to_eggs_dir_and_compile(dist, self._dest)]
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/easy_install.py", line 1948, in _move_to_eggs_dir_and_compile
    assert newdist is not None  # newloc above is missing our dist?!
AssertionError

and this on 2'nd

╰ bin/buildout -c tt.cfg
Installing sqla.
Getting distribution for 'sqlalchemy'.
While:
  Installing sqla.
  Getting distribution for 'sqlalchemy'.

An internal error occurred due to a bug in either zc.buildout or in a
recipe being used:
Traceback (most recent call last):
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/buildout.py", line 2250, in main
    getattr(buildout, command)(args)
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/buildout.py", line 855, in install
    installed_files = self[part]._call(recipe.install)
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/buildout.py", line 1651, in _call
    return f()
  File "/Users/ck/.buildout/eggs/zc.recipe.egg-2.0.7-py3.8.egg/zc/recipe/egg/egg.py", line 227, in install
    reqs, ws = self.working_set()
  File "/Users/ck/.buildout/eggs/zc.recipe.egg-2.0.7-py3.8.egg/zc/recipe/egg/egg.py", line 78, in working_set
    ws = self._working_set(
  File "/Users/ck/.buildout/eggs/zc.recipe.egg-2.0.7-py3.8.egg/zc/recipe/egg/egg.py", line 161, in _working_set
    ws = zc.buildout.easy_install.install(
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/easy_install.py", line 971, in install
    return installer.install(specs, working_set)
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/easy_install.py", line 696, in install
    for dist in self._get_dist(requirement, ws):
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/easy_install.py", line 581, in _get_dist
    dists = [_move_to_eggs_dir_and_compile(dist, self._dest)]
  File "/Users/ck/work/reha/new_bo/lib/python3.9/site-packages/zc/buildout/easy_install.py", line 1922, in _move_to_eggs_dir_and_compile
    os.rename(tmp_loc, newloc)
OSError: [Errno 66] Directory not empty: '/Users/ck/.buildout/eggs/tmp5h568bek/SQLAlchemy-1.4.35-py3.9-macosx-11.5-x86_64.egg' -> '/Users/ck/.buildout/eggs/SQLAlchemy-1.4.35-py3.9-macosx-11.5-x86_64.egg'

any idea?

Is it possible to parallelise the building of parts? Could be a huge time saver.

I think what would be needed would be to:

1. Some kind of next_part function which can yield out the next non-dependent part to be built
2. A way to send parts to a forked buildout process
3. A way to receive results from the forked buildout process and write .installed.cfg
4. An output display that shows the progress of forked buildout processes.

Multi-processing, it can't be that hard right?

Perhaps it shouldn't be on by default - I think some people express decencies by the order of the buildout:parts value.

If I am using a downloads cache and install a package those name contains a hyphen which is not in the eggs directory I get PkgResourcesDeprecationWarnings about invalid version numbers.

See the following example:

Contents of buildout.cfg:

[buildout]
parts = test
eggs-directory = eggs
download-cache = cache

[test]
recipe = zc.recipe.egg
eggs = pytest-cov

Example output:

$ python3.9 -m venv deprec-warn
$ cd deprec-warn/
$ bin/pip install -U pip setuptools wheel "zc.buildout==3.0.0b5"
...
Successfully installed pip-21.3.1 setuptools-59.4.0 wheel-0.37.0 zc.buildout-3.0.0b5
cat > buildout.cfg << EOF
[buildout]
parts = test
eggs-directory = eggs
download-cache = cache

[test]
recipe = zc.recipe.egg
eggs = pytest-cov
EOF
$ bin/buildout
Creating directory '/.../deprec-warn/cache'.
Creating directory '/.../deprec-warn/eggs/cp39'.
Creating directory '/.../deprec-warn/parts'.
Creating directory '/.../deprec-warn/develop-eggs'.
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning:  is an invalid version and will not be supported in a future release
  warnings.warn(
Getting distribution for 'zc.recipe.egg>=2.0.6'.
Got zc.recipe.egg 2.0.7.
Installing test.
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-0.6 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning:  is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-0.7 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-0.8 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-0.9 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-0.10 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-0.11 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-0.12 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-0.13 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-0.14 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-0.15 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-1.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-1.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-1.2 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-1.3 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-1.4 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-1.5 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-1.6 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-1.7.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-1.8.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-1.8.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.0.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.1.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.2.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.2.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.3.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.3.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.4.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.5.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.5.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.6.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.6.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.7.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.7.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.8.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.8.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.9.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.10.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.10.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.11.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.11.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.12.0 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-2.12.1 is an invalid version and will not be supported in a future release
  warnings.warn(
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning: cov-3.0.0 is an invalid version and will not be supported in a future release
  warnings.warn(
Getting distribution for 'pytest-cov'.
Got pytest-cov 3.0.0.
Getting distribution for 'pytest>=4.6'.
Got pytest 6.2.5.
Getting distribution for 'coverage[toml]>=5.2.1'.
Got coverage 6.2.
Getting distribution for 'toml'.
Got toml 0.10.2.
Getting distribution for 'py>=1.8.2'.
Got py 1.11.0.
Getting distribution for 'pluggy<2.0,>=0.12'.
Got pluggy 1.0.0.
Getting distribution for 'packaging'.
Got packaging 21.3.
Getting distribution for 'iniconfig'.
Got iniconfig 1.1.1.
Getting distribution for 'attrs>=19.2.0'.
Got attrs 21.2.0.
Getting distribution for 'tomli'.
Got tomli 1.2.2.
Getting distribution for 'pyparsing!=3.0.5,>=2.0.2'.
Got pyparsing 3.0.6.
$

The interesting warnings seem to be the one without a version number and that each existing version of pytest-cov gets a warning.

Repreated calls to bin/buildout show just one warning for an empty version number:

$ bin/buildout
/.../deprec-warn/lib/python3.9/site-packages/pkg_resources/__init__.py:116: PkgResourcesDeprecationWarning:  is an invalid version and will not be supported in a future release
  warnings.warn(
Updating test.
$