'InvalidSpecifier: ==not' when converting from Pipfile.lock

[intgr]

Short description

Conversion from Pipfile.lock almost always fails with error "ERROR InvalidSpecifier: ==not in3.0"

cd /empty/directory
pipenv install requests
dephell deps convert --from-format=pipfilelock --from-path=Pipfile.lock --to-format=pipfile --to-path=Pipfile.x --level=DEBUG

Output

WARNING cannot find config file
DEBUG load dependencies... (format=pipfilelock, path=Pipfile.lock)
DEBUG dump dependencies... (format=pipfile, path=Pipfile.x)
ERROR InvalidSpecifier: ==not in3.0

I suspect it's due to markers in Pipfile.lock:

        "urllib3": {
            "hashes": [...],
            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4' and python_version < '4'",
            "version": "==1.25.10"
        }

Steps to reproduce

cd /empty/directory
pipenv install requests
dephell deps convert --from-format=pipfilelock --from-path=Pipfile.lock --to-format=pipfile --to-path=Pipfile.x --level=DEBUG

Traceback

Traceback (most recent call last):
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell/cli.py", line 66, in main
    result = handler()
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell/commands/deps_convert.py", line 91, in __call__
    dumper.dump(path=self.config['to']['path'], **dumper_kwargs)
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell/converters/base.py", line 74, in dump
    content = self.dumps(reqs=reqs, content=content, project=project)
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell/converters/pipfile.py", line 160, in dumps
    doc[section][raw_name] = self._format_req(req=req)
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell/converters/pipfile.py", line 202, in _format_req
    for name, value in req:
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell/models/requirement.py", line 248, in __iter__
    value = getattr(self, name)
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell/cached_property.py", line 18, in __get__
    value = obj.__dict__[self.func.__name__] = self.func(obj)
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell/models/requirement.py", line 147, in python
    python = self.dep.marker.python_version
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell/models/marker_tracker.py", line 43, in __getattr__
    return getattr(self.markers, name)
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell_markers/_markers.py", line 57, in python_version
    return RangeSpecifier(value)
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell_specifier/range_specifier.py", line 40, in __init__
    self._specs = self._parse(spec)
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell_specifier/range_specifier.py", line 73, in _parse
    result.add(Specifier(constr))
  File "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell_specifier/specifier.py", line 62, in __init__
    raise specifiers.InvalidSpecifier(constr)
packaging.specifiers.InvalidSpecifier: ==not in3.0

Versions

{
  "cache": "1.90Mb",
  "path": "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/lib/python3.8/site-packages/dephell",
  "python": "/Users/marti.raudsepp/.local/share/git/virtualenvs/b-LbqoOGsB/bin/python",
  "version": "0.8.3",
  "versions": {
    "dephell-archive": "0.1.7",
    "dephell-argparse": "0.1.3",
    "dephell-changelogs": "0.0.1",
    "dephell-discover": "0.2.10",
    "dephell-licenses": "0.1.7",
    "dephell-links": "0.1.5",
    "dephell-markers": "1.0.3",
    "dephell-pythons": "0.1.15",
    "dephell-setuptools": "0.2.4",
    "dephell-shells": "0.1.5",
    "dephell-specifier": "0.2.2",
    "dephell-venvs": "0.1.17",
    "dephell-versioning": "0.1.2"
  }
}