• 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: Ubuntu 18.04
• Poetry version: 1.0.0a2
• Link of a Gist with the contents of your pyproject.toml file:

[tool.poetry]
name = "poetry_bug"
version = "0.1.0"
description = ""
authors = ["Steven Pate <steven@laac.dev>"]

[tool.poetry.dependencies]
python = "^3.6"
django = "^2.1"

[tool.poetry.dev-dependencies]
pytest = "^4.2"
webassets = {git = "https://github.com/miracle2k/webassets.git"}

[build-system]
requires = ["poetry>=0.12"]
build-backend = "poetry.masonry.api"

Issue

First off, poetry is awesome. Thank you for a great step forward in Python dependency management.

Using the above pyproject.toml, I run poetry export -f requirements.txt, and it produces this requirements.txt

django==2.1.5 \
    --hash=sha256:a32c22af23634e1d11425574dce756098e015a165be02e4690179889b207c7a8 \
    --hash=sha256:d6393918da830530a9516bbbcbf7f1214c3d733738779f06b0f649f49cc698c3
pytz==2018.9 \
    --hash=sha256:32b0891edff07e28efe91284ed9c31e123d84bea3fd98e1f72be2508f43ef8d9 \
    --hash=sha256:d5f05e487007e29e03409f9398d074e158d920d36eb82eaf66fb1136b0c5374c
-e git+https://github.com/miracle2k/webassets.git@d1f3455e383446ca4ab0c644f326ee937e68e809#egg=webassets

webassets is included in the requirements.txt without adding the --dev to the export command.