pipenv: Unable to lock from private PyPI

I am currently unable to lock my Pipfile when using our private PyPI sources on 2018.11.14. This issue hadn’t appeared on prior versions of pipenv. I suppose it’s possible that our private PyPI sources are the problem, but I’m not sure what could be happening.

This is an example Pipfile that causes the error:

[[source]]
url = "http://<private-pypi-host>/simple/"
verify_ssl = false
name = "private-pypi"

[packages]
moto = "==1.3.6"

[dev-packages]

[requires]

Running pipenv install yields the following logs:

Creating a virtualenv for this project…
Pipfile: /Pipfile
Using /usr/local/bin/python (3.7.1) to create virtualenv…
✔ Complete 
Already using interpreter /usr/local/bin/python
Using base prefix '/usr/local'
New python executable in /root/.local/share/virtualenvs/-x-v5uFv0/bin/python
Installing setuptools, pip, wheel...
done.
Virtualenv location: /root/.local/share/virtualenvs/-x-v5uFv0
Pipfile.lock not found, creating…
Locking [dev-packages] dependencies…
Locking [packages] dependencies…
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/pexpect/expect.py", line 109, in expect_loop
    return self.timeout()
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/pexpect/expect.py", line 82, in timeout
    raise TIMEOUT(msg)
pexpect.exceptions.TIMEOUT: <pexpect.popen_spawn.PopenSpawn object at 0x7f85959d7f98>
searcher: searcher_re:
    0: re.compile('\n')

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/bin/pipenv", line 11, in <module>
    sys.exit(cli())
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/click/core.py", line 764, in __call__
    return self.main(*args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/click/core.py", line 717, in main
    rv = self.invoke(ctx)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/click/core.py", line 1137, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/click/core.py", line 956, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/click/decorators.py", line 64, in new_func
    return ctx.invoke(f, obj, *args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/click/core.py", line 555, in invoke
    return callback(*args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/click/decorators.py", line 17, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/pipenv/cli/command.py", line 249, in install
    editable_packages=state.installstate.editables,
  File "/usr/local/lib/python3.7/site-packages/pipenv/core.py", line 1872, in do_install
    keep_outdated=keep_outdated
  File "/usr/local/lib/python3.7/site-packages/pipenv/core.py", line 1223, in do_init
    pypi_mirror=pypi_mirror,
  File "/usr/local/lib/python3.7/site-packages/pipenv/core.py", line 1047, in do_lock
    lockfile=lockfile
  File "/usr/local/lib/python3.7/site-packages/pipenv/utils.py", line 620, in venv_resolve_deps
    c = resolve(cmd, sp)
  File "/usr/local/lib/python3.7/site-packages/pipenv/utils.py", line 503, in resolve
    result = c.expect(u"\n", timeout=environments.PIPENV_TIMEOUT)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/delegator.py", line 215, in expect
    self.subprocess.expect(pattern=pattern, timeout=timeout)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/pexpect/spawnbase.py", line 341, in expect
    timeout, searchwindowsize, async_)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/pexpect/spawnbase.py", line 369, in expect_list
    return exp.expect_loop(timeout)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/pexpect/expect.py", line 119, in expect_loop
    return self.timeout(e)
  File "/usr/local/lib/python3.7/site-packages/pipenv/vendor/pexpect/expect.py", line 82, in timeout
    raise TIMEOUT(msg)
pexpect.exceptions.TIMEOUT: <pexpect.popen_spawn.PopenSpawn object at 0x7f85959d7f98>
searcher: searcher_re:
    0: re.compile('\n')
<pexpect.popen_spawn.PopenSpawn object at 0x7f85959d7f98>
searcher: searcher_re:
    0: re.compile('\n')

Replacing the [[source]] section with the default appears to resolve the issue, but then I’m unable to install private pips.

{'implementation_name': 'cpython',
 'implementation_version': '3.7.1',
 'os_name': 'posix',
 'platform_machine': 'x86_64',
 'platform_python_implementation': 'CPython',
 'platform_release': '4.9.93-linuxkit-aufs',
 'platform_system': 'Linux',
 'platform_version': '#1 SMP Wed Jun 6 16:55:56 UTC 2018',
 'python_full_version': '3.7.1',
 'python_version': '3.7',
 'sys_platform': 'linux'}

[[source]]
url = "http://public-pypi.service.dc1.consul/simple/"
verify_ssl = false
name = "public-pypi"

[packages]
moto = "==1.3.6"

[dev-packages]

[requires]