Environment markers do not carry out to transitive dependencies #563
Description
As in title.
Environment Versions
Ubuntu 14.04, pip-tools 1.9.0, pip 9.0.1, python 2.7 + 3.4
Steps to replicate
Imagine some package 'foo` that requires:
enum34; python_version < '3.4'
Require foo in requirements.txt:
foo
With python 2.7, when you run pip-compile requirements.txt...
Expected result
#
# This file is autogenerated by pip-compile
# To update, run:
#
# pip-compile --output-file requirements.txt requirements.in
#
enum34==1.1.6; python_version < '3.4' # via foo
foo==1.0.0
Actual result
#
# This file is autogenerated by pip-compile
# To update, run:
#
# pip-compile --output-file requirements.txt requirements.in
#
enum34==1.1.6 # via foo
foo==1.0.0
So environment marker is not carried on.
If you run with python3.4+, whole enum34 is omitted.