Drop support for PyPy (refer to readme update for details)

Author: xolox

.travis.yml

@@ -1,7 +1,3 @@
-# Note to self: PyPy is not included here because the installation of Bazaar
-# fails on Travis CI even though it works just fine on my local system?! (I'm
-# using PyPy from https://launchpad.net/~pypy/+archive/ubuntu/ppa)
-
 language: python
 python:
   - "2.6"

README.rst

@@ -9,9 +9,8 @@ vcs-repo-mgr: Version control repository manager
 
 The Python package `vcs-repo-mgr` provides a command line program and Python
 API to perform common operations (in the context of packaging/deployment) on
-`version control`_ repositories. It's currently tested on cPython 2.6, 2.7, 3.4
-and 3.5 and PyPy (2.7). Bazaar_, Mercurial_ and Git_ repositories are currently
-supported.
+`version control`_ repositories. It's currently tested on Python 2.6, 2.7, 3.4
+and 3.5. Bazaar_, Mercurial_ and Git_ repositories are supported.
 
 .. contents::
    :local:
@@ -308,6 +307,43 @@ of these improvements, I'm just thinking out loud ;-).
  and Mercurial_ repositories. To be honest I'm not sure this is worth the
  effort, I find myself working with Bazaar repositories less and less.
 
+Known issues
+------------
+
+This section documents known issues that users may run into.
+
+Problematic dependencies
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+Bazaar and Mercurial are both written in Python and available on PyPI and as
+such I included them in the installation requirements of `vcs-repo-mgr`,
+because I couldn't think of a good reason not to.
+
+Adding support for Python 3 to `vcs-repo-mgr` made things more complicated
+because Bazaar and Mercurial didn't support Python 3, leading to installation
+errors. To cope with this problem the Bazaar and Mercurial requirements were
+made conditional on the Python version:
+
+- On Python 2 the Bazaar and Mercurial packages would be installed together
+  with `vcs-repo-mgr`.
+
+- On Python 3 the user was instead responsible for making sure that Bazaar and
+  Mercurial were installed (for example using system packages).
+
+This works fine because `vcs-repo-mgr` only invokes Bazaar and Mercurial using
+the command line interfaces so it doesn't matter whether the version control
+system is using the same version of Python as `vcs-repo-mgr`.
+
+Since then the installation of the Bazaar package has started failing on PyPy,
+unfortunately this time there is no reliable and backwards compatible way to
+make the Bazaar dependency optional in wheel distributions `due to bugs in
+setuptools <https://github.com/html5lib/html5lib-python/issues/231#issuecomment-224022399>`_.
+
+When I investigated support for environment markers that match Python
+implementations (refer to the link above) I decided that instead of writing a
+setup script full of nasty and fragile hacks I'd rather just drop official
+(tested) support for PyPy, as silly as the reason for it may be.
+
 Contact
 -------
 

setup.py

@@ -3,7 +3,7 @@
 # Setup script for the `vcs-repo-mgr' package.
 #
 # Author: Peter Odding <peter@peterodding.com>
-# Last Change: August 4, 2016
+# Last Change: October 25, 2016
 # URL: https://github.com/xolox/python-vcs-repo-mgr
 
 """
@@ -136,8 +136,6 @@ def have_environment_marker_support():
           'Programming Language :: Python :: 3',
           'Programming Language :: Python :: 3.4',
           'Programming Language :: Python :: 3.5',
-          'Programming Language :: Python :: Implementation :: CPython',
-          'Programming Language :: Python :: Implementation :: PyPy',
           'Topic :: Software Development :: Libraries :: Python Modules',
           'Topic :: Software Development :: Version Control',
           'Topic :: System :: Archiving :: Packaging',

tox.ini

@@ -4,7 +4,7 @@
 # directory.
 
 [tox]
-envlist = py26, py27, py34, py35, pypy
+envlist = py26, py27, py34, py35
 
 [testenv]
 deps =