Vendor pip 9.0.3

.appveyor.yml

@@ -1,22 +1,10 @@
 environment:
 
     matrix:
-        - TOXENV: py27-pip8
-        - TOXENV: py27-pip8.1.1
-        - TOXENV: py27-pip9
-        - TOXENV: py27-piplatest
-        - TOXENV: py34-pip8
-        - TOXENV: py34-pip8.1.1
-        - TOXENV: py34-pip9
-        - TOXENV: py34-piplatest
-        - TOXENV: py35-pip8
-        - TOXENV: py35-pip8.1.1
-        - TOXENV: py35-pip9
-        - TOXENV: py35-piplatest
-        - TOXENV: py36-pip8
-        - TOXENV: py36-pip8.1.1
-        - TOXENV: py36-pip9
-        - TOXENV: py36-piplatest
+        - TOXENV: py27
+        - TOXENV: py34
+        - TOXENV: py35
+        - TOXENV: py36
 
 install:
     - C:\Python36\python -m pip install tox

.coveragerc

@@ -0,0 +1,6 @@
+[run]
+branch = True
+source = piptools
+omit =
+    piptools/_compat/*
+    piptools/_vendored/*

.flake8

@@ -1,3 +1,3 @@
 [flake8]
 max-line-length = 120
-exclude = build/*, dist/*, pip_tools.egg-info/*, piptools/_compat/*
+exclude = build/*, dist/*, pip_tools.egg-info/*, piptools/_compat/*, piptools/_vendored/*

.travis.yml

@@ -6,11 +6,6 @@ python:
   - "3.5"
   - "3.6"
   - "pypy"
-env:
-  - PIP=8
-  - PIP=8.1.1
-  - PIP=9
-  - PIP=latest
 
 cache: pip
 install:

README.rst

@@ -34,7 +34,6 @@ recommended to install ``pip-tools`` in each project's `virtual environment`_:
 .. code-block:: bash
 
     $ source /path/to/venv/bin/activate
-    (venv)$ pip install --upgrade pip  # pip-tools needs pip==8.0 or higher (!)
     (venv)$ pip install pip-tools
 
 **Note**: all of the remaining example commands assume you've activated your
@@ -226,6 +225,17 @@ If you use multiple Python versions, you can run ``pip-sync`` as
 ``setuptools``, ``pip``, or ``pip-tools`` itself. Use ``pip install --upgrade``
 to upgrade those packages.
 
+
+Note about ``pip``
+==================
+
+As of v2.0.0, pip-tools has vendored ``pip v9.0.3`` in its codebase.
+This was done to keep ``pip-tools`` working for users with ``pip v10.0.0``.
+Only the ``pip-sync`` command still use the ``pip`` found in the ``virtualenv``,
+and only for the ``pip install`` and ``pip uninstall`` commands issued as shell-outs
+by ``pip-sync``.
+
+
 Other useful tools
 ==================
 

piptools/__init__.py

@@ -0,0 +1,6 @@
+import os
+import sys
+
+# Inject vendored directory into system path.
+v_path = os.path.abspath(os.path.sep.join([os.path.dirname(os.path.realpath(__file__)), '_vendored']))
+sys.path.insert(0, v_path)

piptools/_vendored/README.rst

@@ -0,0 +1,29 @@
+Vendored libs policy
+====================
+
+* Vendored libraries **MUST** not be modified except as required to
+  successfully vendor them.
+
+* Vendored libraries **MUST** be released copies of libraries available on
+  PyPI.
+
+* The versions of libraries vendored in pip-tools **MUST** be reflected
+  in the section below.
+
+* Vendored libraries **MUST** function without any build steps such as 2to3 or
+  compilation of C code, practically this limits to single source 2.x/3.x and
+  pure Python.
+
+* Any modifications made to libraries **MUST** be noted in the section below.
+
+
+Versions and modifications:
+===========================
+
+* ``pip`` == 9.0.3
+
+  Modifications:
+    - None.
+
+  Reason: ``pip`` 10.x internal changes break the dependency resolution code for ``pip-compile``.
+    Note that ``pip-sync`` still uses the user-installed ``pip`` to perform the install/uninstall operations.