Lock fails with flit = "*" in dev packages

The pipenv lock command fails when I have flit = "*" in my dev-packages section of Pipfile. Tried as well with flit in the packages section, same result.

I understand that it might be because flit is different and may not be already supported by pip or else, so feel free to close if this has nothing to do with pipenv 😺

$ python -m pipenv.help output

Pipenv version: '11.9.0'

Pipenv location: '/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv'

Python location: '/home/pawamoy/.local/venvs/pipenv/bin/python'

Other Python installations in PATH:

• 2.7: /home/pawamoy/.pyenv/shims/python2.7

• 2.7: /home/pawamoy/.pyenv/shims/python2.7

• 2.7: /home/pawamoy/.pyenv/shims/python2.7

• 2.7: /usr/bin/python2.7

• 3.4: /usr/bin/python3.4m

• 3.4: /usr/bin/python3.4

• 3.5: /home/pawamoy/.pyenv/shims/python3.5m

• 3.5: /home/pawamoy/.local/venvs/pipenv/bin/python3.5

• 3.5: /home/pawamoy/.pyenv/shims/python3.5

• 3.5: /home/pawamoy/.pyenv/shims/python3.5

• 3.6: /home/pawamoy/.pyenv/shims/python3.6m

• 3.6: /home/pawamoy/.pyenv/shims/python3.6

• 3.6: /home/pawamoy/.pyenv/shims/python3.6

• 3.7: /home/pawamoy/.pyenv/shims/python3.7m

• 3.7: /home/pawamoy/.pyenv/shims/python3.7

• 3.7: /home/pawamoy/.pyenv/shims/python3.7

• 3.5.5: /home/pawamoy/.local/venvs/pipenv/bin/python

• 3.5.5: /home/pawamoy/.pyenv/shims/python

• 3.5.5: /home/pawamoy/.pyenv/shims/python

• 2.7.9: /usr/bin/python

• 2.7.9: /home/pawamoy/.pyenv/shims/python2

• 2.7.9: /home/pawamoy/.pyenv/shims/python2

• 2.7.9: /usr/bin/python2

• 3.5.5: /home/pawamoy/.local/venvs/pipenv/bin/python3

• 3.5.5: /home/pawamoy/.pyenv/shims/python3

• 3.5.5: /home/pawamoy/.pyenv/shims/python3

• 3.4.2: /usr/bin/python3

PEP 508 Information:

{'implementation_name': 'cpython',
 'implementation_version': '3.5.5',
 'os_name': 'posix',
 'platform_machine': 'x86_64',
 'platform_python_implementation': 'CPython',
 'platform_release': '3.16.0-5-amd64',
 'platform_system': 'Linux',
 'platform_version': '#1 SMP Debian 3.16.51-3+deb8u1 (2018-01-08)',
 'python_full_version': '3.5.5',
 'python_version': '3.5',
 'sys_platform': 'linux'}

System environment variables:

• XDG_SESSION_PATH
• GOENV_SHELL
• USER
• PYTHONDONTWRITEBYTECODE
• BASH_FUNC_shellm-include%%
• PS4
• XAUTHORITY
• EDITOR_GUI
• SHELLHISTORY_FILE
• OLDPWD
• BASH_FUNC_shellm-ndef%%
• XDG_SESSION_ID
• EDITOR
• XDG_VTNR
• RBENV_SHELL
• PS1
• BASH_FUNC_shellm-define%%
• _
• PWD
• BASH_FUNC_shellm%%
• BASHER_ROOT
• BASHER_SHELL
• LOGNAME
• SHELLM_PROJECT
• DESKTOP_SESSION
• BASH_FUNC_shellm-find-lib%%
• LANG
• SSH_AUTH_SOCK
• HISTTIMEFORMAT
• EDITOR_CLI
• HISTSIZE
• DISPLAY
• PYTHONUNBUFFERED
• HISTFILESIZE
• WINDOWID
• SSH_AGENT_PID
• XDG_SEAT
• INSTALLED
• GPG_AGENT_INFO
• SHENV_ROOT
• PACKAGE_HOME
• XDG_GREETER_DATA_DIR
• HOME
• SHENV_SHELL
• PYDJAMAS
• MANPATH
• WORKON_HOME
• PROJECT_HOME
• _SHELLHISTORY_UUID
• BASH_FUNC_shellm-exclude%%
• ISOLATED
• FILEMANAGER_CLI
• BUILD_A_SPACE
• QT_STYLE_OVERRIDE
• SHELLHISTORY_VENV
• PIP_PYTHON_PATH
• GOPATH
• PAPERLESS_PASSPHRASE
• BASH_FUNC_shenv%%
• DBUS_SESSION_BUS_ADDRESS
• XDG_SEAT_PATH
• TERM
• DATA
• SHENV_VERSION
• XDG_CURRENT_DESKTOP
• VISUAL
• GDMSESSION
• SHENV_HOOK_PATH
• PYENV_SHELL
• SHENV_DIR
• TERMINATOR_UUID
• BASHER_PREFIX
• GIT_HOME
• PAPERLESS_CONSUMPTION_DIR
• SHELL
• BASH_FUNC_shellm-find-script%%
• SHELLM_PROJECT_PROFILE
• SHLVL
• XDG_RUNTIME_DIR
• KEYCUT_DATA
• PATH
• BASH_FUNC_man%%
• LIBPATH
• GIT_PS1_SHOWCOLORHINTS
• COLORTERM
• VIRTUAL_ENV
• FILEMANAGER_GUI
• LANGUAGE
• LS_COLORS

Pipenv–specific environment variables:

Debug–specific environment variables:

• PATH: /home/pawamoy/.local/venvs/pipenv/bin:/home/pawamoy/.basher/cellar/bin:/home/pawamoy/.basher/bin:/home/pawamoy/.local/bin:/home/pawamoy/.shenv/shims:/home/pawamoy/.shenv/bin:/home/pawamoy/.go/bin:/home/pawamoy/.goenv/shims:/home/pawamoy/.goenv/bin:/home/pawamoy/.pyenv/shims:/home/pawamoy/.pyenv/bin:/home/pawamoy/.rbenv/shims:/home/pawamoy/.rbenv/bin:/home/pawamoy/.shenv/versions/bash-4.4.12/bin:/home/pawamoy/.shenv/libexec:/home/pawamoy/.shenv/plugins/shell-build/bin:/home/pawamoy/.basher/cellar/bin:/home/pawamoy/.basher/bin:/home/pawamoy/.local/bin:/home/pawamoy/.shenv/shims:/home/pawamoy/.shenv/bin:/home/pawamoy/.go/bin:/home/pawamoy/.goenv/shims:/home/pawamoy/.goenv/bin:/home/pawamoy/.pyenv/shims:/home/pawamoy/.pyenv/bin:/home/pawamoy/.rbenv/shims:/home/pawamoy/.rbenv/bin:/media/pawamoy/Data/git/pawamoy/shellmpawamoy/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
• SHELL: /bin/bash
• EDITOR: /usr/bin/vim
• LANG: en_US.UTF-8
• PWD: /media/pawamoy/Data/git/pawamoy/neopy
• VIRTUAL_ENV: /home/pawamoy/.local/venvs/pipenv

---

Contents of Pipfile (‘/media/pawamoy/Data/git/pawamoy/neopy/Pipfile’):

[[source]]
url = "https://pypi.python.org/simple"
verify_ssl = true
name = "pypi"

[requires]
python_version = "3.5"

[dev-packages]
ipython = "*"
pytest = "*"
pytest-sugar = "*"
pypandoc = "*"
flit = "*"

[packages]
"neo4j-driver" = "*"

---

Expected result

No errors 😁

Actual result

$ pipenv lock --verbose
Locking [dev-packages] dependencies…
Using pip: -i https://pypi.python.org/simple

                          ROUND 1                           
Current constraints:
  flit

Finding the best candidates:

Traceback (most recent call last):
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/vendor/pip9/_vendor/packaging/specifiers.py", line 601, in __init__
    parsed.add(Specifier(specifier))
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/vendor/pip9/_vendor/packaging/specifiers.py", line 85, in __init__
    raise InvalidSpecifier("Invalid specifier: '{0}'".format(spec))
pip9._vendor.packaging.specifiers.InvalidSpecifier: Invalid specifier: '3'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/resolver.py", line 82, in <module>
    main()
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/resolver.py", line 71, in main
    clear=do_clear,
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/resolver.py", line 63, in resolve
    verbose=verbose,
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/utils.py", line 425, in resolve_deps
    pre,
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/utils.py", line 336, in actually_resolve_reps
    resolved_tree.update(resolver.resolve(max_rounds=PIPENV_MAX_ROUNDS))
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/patched/piptools/resolver.py", line 102, in resolve
    has_changed, best_matches = self._resolve_one_round()
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/patched/piptools/resolver.py", line 193, in _resolve_one_round
    best_matches = {self.get_best_match(ireq) for ireq in constraints}
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/patched/piptools/resolver.py", line 193, in <setcomp>
    best_matches = {self.get_best_match(ireq) for ireq in constraints}
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/patched/piptools/resolver.py", line 257, in get_best_match
    best_match = self.repository.find_best_match(ireq, prereleases=self.prereleases)
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/patched/piptools/repositories/pypi.py", line 116, in find_best_match
    all_candidates = self.find_all_candidates(ireq.name)
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/patched/piptools/repositories/pypi.py", line 101, in find_all_candidates
    candidates = self.finder.find_all_candidates(req_name)
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/patched/notpip/index.py", line 460, in find_all_candidates
    self._package_versions(page.links, search)
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/patched/notpip/index.py", line 635, in _package_versions
    v = self._link_package_versions(link, search)
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/patched/notpip/index.py", line 707, in _link_package_versions
    support_this_python = check_requires_python(link.requires_python)
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/patched/notpip/utils/packaging.py", line 30, in check_requires_python
    requires_python_specifier = specifiers.SpecifierSet(requires_python)
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/vendor/pip9/_vendor/packaging/specifiers.py", line 603, in __init__
    parsed.add(LegacySpecifier(specifier))
  File "/home/pawamoy/.local/venvs/pipenv/lib/python3.5/site-packages/pipenv/vendor/pip9/_vendor/packaging/specifiers.py", line 85, in __init__
    raise InvalidSpecifier("Invalid specifier: '{0}'".format(spec))
pip9._vendor.packaging.specifiers.InvalidSpecifier: Invalid specifier: '3'

Steps to replicate

mkdir test_project
cd test_project
pipenv install --dev flit

[osteele]

if you are trying to teach us about python specifiers we are pretty familiar with them

I didn’t mean to condescend. I was trying to record the information that (1) I learned while trying to dig deeper into the issue and that (2) looked relevant to the scope of the issue (whether it’s likely to be just flit, or might affect other packages too). In other projects, I’ve found it helpful when people leave notes about what they’ve learned so that other people can pick up where they left off. I’ll be more minimal if I interact with this project again.

If you would like to be constructive please open an issue describing your problem with an example

Done: #2343. I was trying to be constructive above, and I’m trying to be constructive in that bug report too. I remain open to feedback about whether I’ve accomplished that and what I can do to improve, although I would appreciate it if it came from an assumption of good faith.

As far as I know there is nothing about flit that makes it incompatible with pipenv

My understanding of this issue is that it reports an unresolved incompatibility between flit and pipenv, and that it was closed, effectively, as “will not fix”. My question was whether there’s a workaround, since I was unable to find one.

I don’t know why you are linking 10 year old peps

To explain why the package repository might contain packages with versions such as Requires-Python: 3. This seems like it might bear on the scope of the issue. I considered the upside that more information might be useful; I didn’t consider that including it might be offensive.

I’m not super interested in having negative interactions today

Me neither! Or ever! Please give me the benefit of a doubt — I may have written confusingly, but not malevolently, and was surprised to receive a harsh response.

[techalchemy]

hi @osteele, I am not really following what you are saying here, but if you are trying to teach us about python specifiers we are pretty familiar with them. If you would like to be constructive please open an issue describing your problem with an example.

Is there a workaround, or is flit permanently incompatible with pipenv?

As far as I know there is nothing about flit that makes it incompatible with pipenv, I don’t know why you are linking 10 year old peps, but I’m not super interested in having negative interactions today so if you want to describe a problem or a bug and you are hoping to solve it productively, please open an issue and fill out the issue template