'[IndexError] list index out of range' on poetry install in Docker if packages is specified

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

• OS version and name: python:3.7-alpine3.11 (Docker)
• Poetry version: 1.0.2
• Link of a Gist with the contents of your pyproject.toml file: https://gist.github.com/kbakk/0811ab3d4a7e90f3141c2c2d4ac2be3e

Issue

A common technique when creating a Dockerfile is to copy pyproject.toml and poetry.lock, then running poetry install.

Like so:

COPY pyproject.toml poetry.lock ./
RUN poetry install --no-dev 
# then, add the rest of the project to only run
# poetry install when pyproject.toml/poetry.lock changes
COPY . /app

However, if the project is contains packages (see example pyproject.toml linked above), poetry will fail to find these, as they hasn’t been copied over yet, and throw error:

[IndexError]
list index out of range

Traceback (most recent call last):
  File "/root/.poetry/lib/poetry/_vendor/py3.7/clikit/console_application.py", line 131, in run
    status_code = command.handle(parsed_args, io)
  File "/root/.poetry/lib/poetry/_vendor/py3.7/clikit/api/command/command.py", line 120, in handle
    status_code = self._do_handle(args, io)
  File "/root/.poetry/lib/poetry/_vendor/py3.7/clikit/api/command/command.py", line 171, in _do_handle
    return getattr(handler, handler_method)(args, io, self)
  File "/root/.poetry/lib/poetry/_vendor/py3.7/cleo/commands/command.py", line 92, in wrap_handle
    return self.handle()
  File "/root/.poetry/lib/poetry/console/commands/install.py", line 72, in handle
    builder = EditableBuilder(self.poetry, self._env, NullIO())
  File "/root/.poetry/lib/poetry/masonry/builders/builder.py", line 68, in __init__
    includes=self._package.include,
  File "/root/.poetry/lib/poetry/masonry/utils/module.py", line 72, in __init__
    source=package.get('from'),
  File "/root/.poetry/lib/poetry/masonry/utils/package_include.py", line 15, in __init__
    self.check_elements()
  File "/root/.poetry/lib/poetry/masonry/utils/package_include.py", line 37, in check_elements
    root = self._elements[0]

One can get around this by installing with --no-root flag:

RUN poetry install --no-dev --no-root

Related: #1247

[mcouthon]

My current workaround for this is as follows:

# Only copying these files here in order to take advantage of Docker cache. We only want the
# next stage (poetry install) to run if these files change, but not the rest of the app.
COPY pyproject.toml poetry.lock ./

# Currently poetry install is significantly slower than pip install, so we're creating a
# requirements.txt output and running pip install with it.
# Follow this issue: https://github.com/python-poetry/poetry/issues/338
# Setting --without-hashes because of this issue: https://github.com/pypa/pip/issues/4995
RUN poetry config virtualenvs.create false \
                && poetry export --without-hashes -f requirements.txt --dev \
                |  poetry run pip install -r /dev/stdin \
                && poetry debug

COPY  . ./

# Because initially we only copy the lock and pyproject file, we can only install the dependencies
# in the RUN above, as the `packages` portion of the pyproject.toml file is not
# available at this point. Now, after the whole package has been copied in, we run `poetry install`
# again to only install packages, scripts, etc. (and thus it should be very quick).
# See this issue for more context: https://github.com/python-poetry/poetry/issues/1899
RUN poetry install --no-interaction

# We're setting the entrypoint to `poetry run` because poetry installed entry points aren't
# available in the PATH by default, but it is available for `poetry run`
ENTRYPOINT ["poetry", "run"]

Hope this helps someone.

[neersighted]

Duplicate #1301.