[pkg] update to versioneer 0.16

1 files changed, 1579 insertions, 474 deletions

diff --git a/mail/versioneer.py b/mail/versioneer.py
index 4e2c0a55..7ed2a21d 100644
--- a/mail/versioneer.py
+++ b/mail/versioneer.py
@@ -1,170 +1,641 @@
-#! /usr/bin/python
 
-"""versioneer.py
+# Version: 0.16
 
-(like a rocketeer, but for versions)
+"""The Versioneer - like a rocketeer, but for versions.
 
+The Versioneer
+==============
+
+* like a rocketeer, but for versions!
 * https://github.com/warner/python-versioneer
 * Brian Warner
 * License: Public Domain
-* Version: 0.7+
-
-This file helps distutils-based projects manage their version number by just
-creating version-control tags.
-
-For developers who work from a VCS-generated tree (e.g. 'git clone' etc),
-each 'setup.py version', 'setup.py build', 'setup.py sdist' will compute a
-version number by asking your version-control tool about the current
-checkout. The version number will be written into a generated _version.py
-file of your choosing, where it can be included by your __init__.py
-
-For users who work from a VCS-generated tarball (e.g. 'git archive'), it will
-compute a version number by looking at the name of the directory created when
-te tarball is unpacked. This conventionally includes both the name of the
-project and a version number.
-
-For users who work from a tarball built by 'setup.py sdist', it will get a
-version number from a previously-generated _version.py file.
-
-As a result, loading code directly from the source tree will not result in a
-real version. If you want real versions from VCS trees (where you frequently
-update from the upstream repository, or do new development), you will need to
-do a 'setup.py version' after each update, and load code from the build/
-directory.
-
-You need to provide this code with a few configuration values:
-
- versionfile_source:
-    A project-relative pathname into which the generated version strings
-    should be written. This is usually a _version.py next to your project's
-    main __init__.py file. If your project uses src/myproject/__init__.py,
-    this should be 'src/myproject/_version.py'. This file should be checked
-    in to your VCS as usual: the copy created below by 'setup.py
-    update_files' will include code that parses expanded VCS keywords in
-    generated tarballs. The 'build' and 'sdist' commands will replace it with
-    a copy that has just the calculated version string.
-
- versionfile_build:
-    Like versionfile_source, but relative to the build directory instead of
-    the source directory. These will differ when your setup.py uses
-    'package_dir='. If you have package_dir={'myproject': 'src/myproject'},
-    then you will probably have versionfile_build='myproject/_version.py' and
-    versionfile_source='src/myproject/_version.py'.
-
- tag_prefix: a string, like 'PROJECTNAME-', which appears at the start of all
-             VCS tags. If your tags look like 'myproject-1.2.0', then you
-             should use tag_prefix='myproject-'. If you use unprefixed tags
-             like '1.2.0', this should be an empty string.
-
- parentdir_prefix: a string, frequently the same as tag_prefix, which
-                   appears at the start of all unpacked tarball filenames. If
-                   your tarball unpacks into 'myproject-1.2.0', this should
-                   be 'myproject-'.
-
-To use it:
-
- 1: include this file in the top level of your project
- 2: make the following changes to the top of your setup.py:
-     import versioneer
-     versioneer.versionfile_source = 'src/myproject/_version.py'
-     versioneer.versionfile_build = 'myproject/_version.py'
-     versioneer.tag_prefix = '' # tags are like 1.2.0
-     versioneer.parentdir_prefix = 'myproject-' # dirname like 'myproject-1.2.0'
- 3: add the following arguments to the setup() call in your setup.py:
-     version=versioneer.get_version(),
-     cmdclass=versioneer.get_cmdclass(),
- 4: run 'setup.py update_files', which will create _version.py, and will
-    modify your __init__.py to define __version__ (by calling a function
-    from _version.py)
- 5: modify your MANIFEST.in to include versioneer.py
- 6: add both versioneer.py and the generated _version.py to your VCS
-"""
+* Compatible With: python2.6, 2.7, 3.3, 3.4, 3.5, and pypy
+* [![Latest Version]
+(https://pypip.in/version/versioneer/badge.svg?style=flat)
+](https://pypi.python.org/pypi/versioneer/)
+* [![Build Status]
+(https://travis-ci.org/warner/python-versioneer.png?branch=master)
+](https://travis-ci.org/warner/python-versioneer)
+
+This is a tool for managing a recorded version number in distutils-based
+python projects. The goal is to remove the tedious and error-prone "update
+the embedded version string" step from your release process. Making a new
+release should be as easy as recording a new tag in your version-control
+system, and maybe making new tarballs.
+
+
+## Quick Install
+
+* `pip install versioneer` to somewhere to your $PATH
+* add a `[versioneer]` section to your setup.cfg (see below)
+* run `versioneer install` in your source tree, commit the results
+
+## Version Identifiers
+
+Source trees come from a variety of places:
+
+* a version-control system checkout (mostly used by developers)
+* a nightly tarball, produced by build automation
+* a snapshot tarball, produced by a web-based VCS browser, like github's
+  "tarball from tag" feature
+* a release tarball, produced by "setup.py sdist", distributed through PyPI
+
+Within each source tree, the version identifier (either a string or a number,
+this tool is format-agnostic) can come from a variety of places:
+
+* ask the VCS tool itself, e.g. "git describe" (for checkouts), which knows
+  about recent "tags" and an absolute revision-id
+* the name of the directory into which the tarball was unpacked
+* an expanded VCS keyword ($Id$, etc)
+* a `_version.py` created by some earlier build step
+
+For released software, the version identifier is closely related to a VCS
+tag. Some projects use tag names that include more than just the version
+string (e.g. "myproject-1.2" instead of just "1.2"), in which case the tool
+needs to strip the tag prefix to extract the version identifier. For
+unreleased software (between tags), the version identifier should provide
+enough information to help developers recreate the same tree, while also
+giving them an idea of roughly how old the tree is (after version 1.2, before
+version 1.3). Many VCS systems can report a description that captures this,
+for example `git describe --tags --dirty --always` reports things like
+"0.7-1-g574ab98-dirty" to indicate that the checkout is one revision past the
+0.7 tag, has a unique revision id of "574ab98", and is "dirty" (it has
+uncommitted changes.
+
+The version identifier is used for multiple purposes:
+
+* to allow the module to self-identify its version: `myproject.__version__`
+* to choose a name and prefix for a 'setup.py sdist' tarball
+
+## Theory of Operation
+
+Versioneer works by adding a special `_version.py` file into your source
+tree, where your `__init__.py` can import it. This `_version.py` knows how to
+dynamically ask the VCS tool for version information at import time.
+
+`_version.py` also contains `$Revision$` markers, and the installation
+process marks `_version.py` to have this marker rewritten with a tag name
+during the `git archive` command. As a result, generated tarballs will
+contain enough information to get the proper version.
+
+To allow `setup.py` to compute a version too, a `versioneer.py` is added to
+the top level of your source tree, next to `setup.py` and the `setup.cfg`
+that configures it. This overrides several distutils/setuptools commands to
+compute the version when invoked, and changes `setup.py build` and `setup.py
+sdist` to replace `_version.py` with a small static file that contains just
+the generated version data.
+
+## Installation
+
+First, decide on values for the following configuration variables:
+
+* `VCS`: the version control system you use. Currently accepts "git".
+
+* `style`: the style of version string to be produced. See "Styles" below for
+  details. Defaults to "pep440", which looks like
+  `TAG[+DISTANCE.gSHORTHASH[.dirty]]`.
+
+* `versionfile_source`:
+
+  A project-relative pathname into which the generated version strings should
+  be written. This is usually a `_version.py` next to your project's main
+  `__init__.py` file, so it can be imported at runtime. If your project uses
+  `src/myproject/__init__.py`, this should be `src/myproject/_version.py`.
+  This file should be checked in to your VCS as usual: the copy created below
+  by `setup.py setup_versioneer` will include code that parses expanded VCS
+  keywords in generated tarballs. The 'build' and 'sdist' commands will
+  replace it with a copy that has just the calculated version string.
+
+  This must be set even if your project does not have any modules (and will
+  therefore never import `_version.py`), since "setup.py sdist" -based trees
+  still need somewhere to record the pre-calculated version strings. Anywhere
+  in the source tree should do. If there is a `__init__.py` next to your
+  `_version.py`, the `setup.py setup_versioneer` command (described below)
+  will append some `__version__`-setting assignments, if they aren't already
+  present.
+
+* `versionfile_build`:
+
+  Like `versionfile_source`, but relative to the build directory instead of
+  the source directory. These will differ when your setup.py uses
+  'package_dir='. If you have `package_dir={'myproject': 'src/myproject'}`,
+  then you will probably have `versionfile_build='myproject/_version.py'` and
+  `versionfile_source='src/myproject/_version.py'`.
+
+  If this is set to None, then `setup.py build` will not attempt to rewrite
+  any `_version.py` in the built tree. If your project does not have any
+  libraries (e.g. if it only builds a script), then you should use
+  `versionfile_build = None`. To actually use the computed version string,
+  your `setup.py` will need to override `distutils.command.build_scripts`
+  with a subclass that explicitly inserts a copy of
+  `versioneer.get_version()` into your script file. See
+  `test/demoapp-script-only/setup.py` for an example.
+
+* `tag_prefix`:
+
+  a string, like 'PROJECTNAME-', which appears at the start of all VCS tags.
+  If your tags look like 'myproject-1.2.0', then you should use
+  tag_prefix='myproject-'. If you use unprefixed tags like '1.2.0', this
+  should be an empty string, using either `tag_prefix=` or `tag_prefix=''`.
+
+* `parentdir_prefix`:
+
+  a optional string, frequently the same as tag_prefix, which appears at the
+  start of all unpacked tarball filenames. If your tarball unpacks into
+  'myproject-1.2.0', this should be 'myproject-'. To disable this feature,
+  just omit the field from your `setup.cfg`.
+
+This tool provides one script, named `versioneer`. That script has one mode,
+"install", which writes a copy of `versioneer.py` into the current directory
+and runs `versioneer.py setup` to finish the installation.
+
+To versioneer-enable your project:
+
+* 1: Modify your `setup.cfg`, adding a section named `[versioneer]` and
+  populating it with the configuration values you decided earlier (note that
+  the option names are not case-sensitive):
+
+  ````
+  [versioneer]
+  VCS = git
+  style = pep440
+  versionfile_source = src/myproject/_version.py
+  versionfile_build = myproject/_version.py
+  tag_prefix =
+  parentdir_prefix = myproject-
+  ````
+
+* 2: Run `versioneer install`. This will do the following:
+
+  * copy `versioneer.py` into the top of your source tree
+  * create `_version.py` in the right place (`versionfile_source`)
+  * modify your `__init__.py` (if one exists next to `_version.py`) to define
+    `__version__` (by calling a function from `_version.py`)
+  * modify your `MANIFEST.in` to include both `versioneer.py` and the
+    generated `_version.py` in sdist tarballs
+
+  `versioneer install` will complain about any problems it finds with your
+  `setup.py` or `setup.cfg`. Run it multiple times until you have fixed all
+  the problems.
+
+* 3: add a `import versioneer` to your setup.py, and add the following
+  arguments to the setup() call:
+
+        version=versioneer.get_version(),
+        cmdclass=versioneer.get_cmdclass(),
+
+* 4: commit these changes to your VCS. To make sure you won't forget,
+  `versioneer install` will mark everything it touched for addition using
+  `git add`. Don't forget to add `setup.py` and `setup.cfg` too.
+
+## Post-Installation Usage
+
+Once established, all uses of your tree from a VCS checkout should get the
+current version string. All generated tarballs should include an embedded
+version string (so users who unpack them will not need a VCS tool installed).
+
+If you distribute your project through PyPI, then the release process should
+boil down to two steps:
+
+* 1: git tag 1.0
+* 2: python setup.py register sdist upload
+
+If you distribute it through github (i.e. users use github to generate
+tarballs with `git archive`), the process is:
+
+* 1: git tag 1.0
+* 2: git push; git push --tags
+
+Versioneer will report "0+untagged.NUMCOMMITS.gHASH" until your tree has at
+least one tag in its history.
+
+## Version-String Flavors
+
+Code which uses Versioneer can learn about its version string at runtime by
+importing `_version` from your main `__init__.py` file and running the
+`get_versions()` function. From the "outside" (e.g. in `setup.py`), you can
+import the top-level `versioneer.py` and run `get_versions()`.
+
+Both functions return a dictionary with different flavors of version
+information:
+
+* `['version']`: A condensed version string, rendered using the selected
+  style. This is the most commonly used value for the project's version
+  string. The default "pep440" style yields strings like `0.11`,
+  `0.11+2.g1076c97`, or `0.11+2.g1076c97.dirty`. See the "Styles" section
+  below for alternative styles.
+
+* `['full-revisionid']`: detailed revision identifier. For Git, this is the
+  full SHA1 commit id, e.g. "1076c978a8d3cfc70f408fe5974aa6c092c949ac".
+
+* `['dirty']`: a boolean, True if the tree has uncommitted changes. Note that
+  this is only accurate if run in a VCS checkout, otherwise it is likely to
+  be False or None
+
+* `['error']`: if the version string could not be computed, this will be set
+  to a string describing the problem, otherwise it will be None. It may be
+  useful to throw an exception in setup.py if this is set, to avoid e.g.
+  creating tarballs with a version string of "unknown".
+
+Some variants are more useful than others. Including `full-revisionid` in a
+bug report should allow developers to reconstruct the exact code being tested
+(or indicate the presence of local changes that should be shared with the
+developers). `version` is suitable for display in an "about" box or a CLI
+`--version` output: it can be easily compared against release notes and lists
+of bugs fixed in various releases.
+
+The installer adds the following text to your `__init__.py` to place a basic
+version in `YOURPROJECT.__version__`:
+
+    from ._version import get_versions
+    __version__ = get_versions()['version']
+    del get_versions
+
+## Styles
+
+The setup.cfg `style=` configuration controls how the VCS information is
+rendered into a version string.
+
+The default style, "pep440", produces a PEP440-compliant string, equal to the
+un-prefixed tag name for actual releases, and containing an additional "local
+version" section with more detail for in-between builds. For Git, this is
+TAG[+DISTANCE.gHEX[.dirty]] , using information from `git describe --tags
+--dirty --always`. For example "0.11+2.g1076c97.dirty" indicates that the
+tree is like the "1076c97" commit but has uncommitted changes (".dirty"), and
+that this commit is two revisions ("+2") beyond the "0.11" tag. For released
+software (exactly equal to a known tag), the identifier will only contain the
+stripped tag, e.g. "0.11".
+
+Other styles are available. See details.md in the Versioneer source tree for
+descriptions.
+
+## Debugging
+
+Versioneer tries to avoid fatal errors: if something goes wrong, it will tend
+to return a version of "0+unknown". To investigate the problem, run `setup.py
+version`, which will run the version-lookup code in a verbose mode, and will
+display the full contents of `get_versions()` (including the `error` string,
+which may help identify what went wrong).
+
+## Updating Versioneer
+
+To upgrade your project to a new release of Versioneer, do the following:
+
+* install the new Versioneer (`pip install -U versioneer` or equivalent)
+* edit `setup.cfg`, if necessary, to include any new configuration settings
+  indicated by the release notes
+* re-run `versioneer install` in your source tree, to replace
+  `SRC/_version.py`
+* commit any changed files
+
+### Upgrading to 0.16
+
+Nothing special.
+
+### Upgrading to 0.15
+
+Starting with this version, Versioneer is configured with a `[versioneer]`
+section in your `setup.cfg` file. Earlier versions required the `setup.py` to
+set attributes on the `versioneer` module immediately after import. The new
+version will refuse to run (raising an exception during import) until you
+have provided the necessary `setup.cfg` section.
+
+In addition, the Versioneer package provides an executable named
+`versioneer`, and the installation process is driven by running `versioneer
+install`. In 0.14 and earlier, the executable was named
+`versioneer-installer` and was run without an argument.
+
+### Upgrading to 0.14
 
-import os, sys, re
-from distutils.core import Command
-from distutils.command.sdist import sdist as _sdist
-from distutils.command.build import build as _build
+0.14 changes the format of the version string. 0.13 and earlier used
+hyphen-separated strings like "0.11-2-g1076c97-dirty". 0.14 and beyond use a
+plus-separated "local version" section strings, with dot-separated
+components, like "0.11+2.g1076c97". PEP440-strict tools did not like the old
+format, but should be ok with the new one.
 
-versionfile_source = None
-versionfile_build = None
-tag_prefix = None
-parentdir_prefix = None
+### Upgrading from 0.11 to 0.12
 
-VCS = "git"
-IN_LONG_VERSION_PY = False
+Nothing special.
 
+### Upgrading from 0.10 to 0.11
 
-LONG_VERSION_PY = '''
-IN_LONG_VERSION_PY = True
+You must add a `versioneer.VCS = "git"` to your `setup.py` before re-running
+`setup.py setup_versioneer`. This will enable the use of additional
+version-control systems (SVN, etc) in the future.
+
+## Future Directions
+
+This tool is designed to make it easily extended to other version-control
+systems: all VCS-specific components are in separate directories like
+src/git/ . The top-level `versioneer.py` script is assembled from these
+components by running make-versioneer.py . In the future, make-versioneer.py
+will take a VCS name as an argument, and will construct a version of
+`versioneer.py` that is specific to the given VCS. It might also take the
+configuration arguments that are currently provided manually during
+installation by editing setup.py . Alternatively, it might go the other
+direction and include code from all supported VCS systems, reducing the
+number of intermediate scripts.
+
+
+## License
+
+To make Versioneer easier to embed, all its code is dedicated to the public
+domain. The `_version.py` that it creates is also in the public domain.
+Specifically, both are released under the Creative Commons "Public Domain
+Dedication" license (CC0-1.0), as described in
+https://creativecommons.org/publicdomain/zero/1.0/ .
+
+"""
+
+from __future__ import print_function
+try:
+    import configparser
+except ImportError:
+    import ConfigParser as configparser
+import errno
+import json
+import os
+import re
+import subprocess
+import sys
+
+
+class VersioneerConfig:
+    """Container for Versioneer configuration parameters."""
+
+
+def get_root():
+    """Get the project root directory.
+
+    We require that all commands are run from the project root, i.e. the
+    directory that contains setup.py, setup.cfg, and versioneer.py .
+    """
+    root = os.path.realpath(os.path.abspath(os.getcwd()))
+    setup_py = os.path.join(root, "setup.py")
+    versioneer_py = os.path.join(root, "versioneer.py")
+    if not (os.path.exists(setup_py) or os.path.exists(versioneer_py)):
+        # allow 'python path/to/setup.py COMMAND'
+        root = os.path.dirname(os.path.realpath(os.path.abspath(sys.argv[0])))
+        setup_py = os.path.join(root, "setup.py")
+        versioneer_py = os.path.join(root, "versioneer.py")
+    if not (os.path.exists(setup_py) or os.path.exists(versioneer_py)):
+        err = ("Versioneer was unable to run the project root directory. "
+               "Versioneer requires setup.py to be executed from "
+               "its immediate directory (like 'python setup.py COMMAND'), "
+               "or in a way that lets it use sys.argv[0] to find the root "
+               "(like 'python path/to/setup.py COMMAND').")
+        raise VersioneerBadRootError(err)
+    try:
+        # Certain runtime workflows (setup.py install/develop in a setuptools
+        # tree) execute all dependencies in a single python process, so
+        # "versioneer" may be imported multiple times, and python's shared
+        # module-import table will cache the first one. So we can't use
+        # os.path.dirname(__file__), as that will find whichever
+        # versioneer.py was first imported, even in later projects.
+        me = os.path.realpath(os.path.abspath(__file__))
+        if os.path.splitext(me)[0] != os.path.splitext(versioneer_py)[0]:
+            print("Warning: build in %s is using versioneer.py from %s"
+                  % (os.path.dirname(me), versioneer_py))
+    except NameError:
+        pass
+    return root
+
+
+def get_config_from_root(root):
+    """Read the project setup.cfg file to determine Versioneer config."""
+    # This might raise EnvironmentError (if setup.cfg is missing), or
+    # configparser.NoSectionError (if it lacks a [versioneer] section), or
+    # configparser.NoOptionError (if it lacks "VCS="). See the docstring at
+    # the top of versioneer.py for instructions on writing your setup.cfg .
+    setup_cfg = os.path.join(root, "setup.cfg")
+    parser = configparser.SafeConfigParser()
+    with open(setup_cfg, "r") as f:
+        parser.readfp(f)
+    VCS = parser.get("versioneer", "VCS")  # mandatory
+
+    def get(parser, name):
+        if parser.has_option("versioneer", name):
+            return parser.get("versioneer", name)
+        return None
+    cfg = VersioneerConfig()
+    cfg.VCS = VCS
+    cfg.style = get(parser, "style") or ""
+    cfg.versionfile_source = get(parser, "versionfile_source")
+    cfg.versionfile_build = get(parser, "versionfile_build")
+    cfg.tag_prefix = get(parser, "tag_prefix")
+    if cfg.tag_prefix in ("''", '""'):
+        cfg.tag_prefix = ""
+    cfg.parentdir_prefix = get(parser, "parentdir_prefix")
+    cfg.verbose = get(parser, "verbose")
+    return cfg
+
+
+class NotThisMethod(Exception):
+    """Exception raised if a method is not valid for the current scenario."""
+
+# these dictionaries contain VCS-specific tools
+LONG_VERSION_PY = {}
+HANDLERS = {}
+
+
+def register_vcs_handler(vcs, method):  # decorator
+    """Decorator to mark a method as the handler for a particular VCS."""
+    def decorate(f):
+        """Store f in HANDLERS[vcs][method]."""
+        if vcs not in HANDLERS:
+            HANDLERS[vcs] = {}
+        HANDLERS[vcs][method] = f
+        return f
+    return decorate
+
+
+def run_command(commands, args, cwd=None, verbose=False, hide_stderr=False):
+    """Call the given command(s)."""
+    assert isinstance(commands, list)
+    p = None
+    for c in commands:
+        try:
+            dispcmd = str([c] + args)
+            # remember shell=False, so use git.cmd on windows, not just git
+            p = subprocess.Popen([c] + args, cwd=cwd, stdout=subprocess.PIPE,
+                                 stderr=(subprocess.PIPE if hide_stderr
+                                         else None))
+            break
+        except EnvironmentError:
+            e = sys.exc_info()[1]
+            if e.errno == errno.ENOENT:
+                continue
+            if verbose:
+                print("unable to run %s" % dispcmd)
+                print(e)
+            return None
+    else:
+        if verbose:
+            print("unable to find command, tried %s" % (commands,))
+        return None
+    stdout = p.communicate()[0].strip()
+    if sys.version_info[0] >= 3:
+        stdout = stdout.decode()
+    if p.returncode != 0:
+        if verbose:
+            print("unable to run %s (error)" % dispcmd)
+        return None
+    return stdout
+LONG_VERSION_PY['git'] = '''
 # This file helps to compute a version number in source trees obtained from
 # git-archive tarball (such as those provided by githubs download-from-tag
-# feature). Distribution tarballs (build by setup.py sdist) and build
+# feature). Distribution tarballs (built by setup.py sdist) and build
 # directories (produced by setup.py build) will contain a much shorter file
 # that just contains the computed version number.
 
 # This file is released into the public domain. Generated by
-# versioneer-0.7+ (https://github.com/warner/python-versioneer)
-
-# these strings will be replaced by git during git-archive
-git_refnames = "%(DOLLAR)sFormat:%%d%(DOLLAR)s"
-git_full = "%(DOLLAR)sFormat:%%H%(DOLLAR)s"
+# versioneer-0.16 (https://github.com/warner/python-versioneer)
 
+"""Git implementation of _version.py."""
 
+import errno
+import os
+import re
 import subprocess
 import sys
 
-def run_command(args, cwd=None, verbose=False):
-    try:
-        # remember shell=False, so use git.exe on windows, not just git
-        p = subprocess.Popen(args, stdout=subprocess.PIPE, cwd=cwd)
-    except EnvironmentError:
-        e = sys.exc_info()[1]
+
+def get_keywords():
+    """Get the keywords needed to look up the version information."""
+    # these strings will be replaced by git during git-archive.
+    # setup.py/versioneer.py will grep for the variable names, so they must
+    # each be defined on a line of their own. _version.py will just call
+    # get_keywords().
+    git_refnames = "%(DOLLAR)sFormat:%%d%(DOLLAR)s"
+    git_full = "%(DOLLAR)sFormat:%%H%(DOLLAR)s"
+    keywords = {"refnames": git_refnames, "full": git_full}
+    return keywords
+
+
+class VersioneerConfig:
+    """Container for Versioneer configuration parameters."""
+
+
+def get_config():
+    """Create, populate and return the VersioneerConfig() object."""
+    # these strings are filled in when 'setup.py versioneer' creates
+    # _version.py
+    cfg = VersioneerConfig()
+    cfg.VCS = "git"
+    cfg.style = "%(STYLE)s"
+    cfg.tag_prefix = "%(TAG_PREFIX)s"
+    cfg.parentdir_prefix = "%(PARENTDIR_PREFIX)s"
+    cfg.versionfile_source = "%(VERSIONFILE_SOURCE)s"
+    cfg.verbose = False
+    return cfg
+
+
+class NotThisMethod(Exception):
+    """Exception raised if a method is not valid for the current scenario."""
+
+
+LONG_VERSION_PY = {}
+HANDLERS = {}
+
+
+def register_vcs_handler(vcs, method):  # decorator
+    """Decorator to mark a method as the handler for a particular VCS."""
+    def decorate(f):
+        """Store f in HANDLERS[vcs][method]."""
+        if vcs not in HANDLERS:
+            HANDLERS[vcs] = {}
+        HANDLERS[vcs][method] = f
+        return f
+    return decorate
+
+
+def run_command(commands, args, cwd=None, verbose=False, hide_stderr=False):
+    """Call the given command(s)."""
+    assert isinstance(commands, list)
+    p = None
+    for c in commands:
+        try:
+            dispcmd = str([c] + args)
+            # remember shell=False, so use git.cmd on windows, not just git
+            p = subprocess.Popen([c] + args, cwd=cwd, stdout=subprocess.PIPE,
+                                 stderr=(subprocess.PIPE if hide_stderr
+                                         else None))
+            break
+        except EnvironmentError:
+            e = sys.exc_info()[1]
+            if e.errno == errno.ENOENT:
+                continue
+            if verbose:
+                print("unable to run %%s" %% dispcmd)
+                print(e)
+            return None
+    else:
         if verbose:
-            print("unable to run %%s" %% args[0])
-            print(e)
+            print("unable to find command, tried %%s" %% (commands,))
         return None
     stdout = p.communicate()[0].strip()
-    if sys.version >= '3':
+    if sys.version_info[0] >= 3:
         stdout = stdout.decode()
     if p.returncode != 0:
         if verbose:
-            print("unable to run %%s (error)" %% args[0])
+            print("unable to run %%s (error)" %% dispcmd)
         return None
     return stdout
 
 
-import sys
-import re
-import os.path
+def versions_from_parentdir(parentdir_prefix, root, verbose):
+    """Try to determine the version from the parent directory name.
+
+    Source tarballs conventionally unpack into a directory that includes
+    both the project name and a version string.
+    """
+    dirname = os.path.basename(root)
+    if not dirname.startswith(parentdir_prefix):
+        if verbose:
+            print("guessing rootdir is '%%s', but '%%s' doesn't start with "
+                  "prefix '%%s'" %% (root, dirname, parentdir_prefix))
+        raise NotThisMethod("rootdir doesn't start with parentdir_prefix")
+    return {"version": dirname[len(parentdir_prefix):],
+            "full-revisionid": None,
+            "dirty": False, "error": None}
 
-def get_expanded_variables(versionfile_source):
+
+@register_vcs_handler("git", "get_keywords")
+def git_get_keywords(versionfile_abs):
+    """Extract version information from the given file."""
     # the code embedded in _version.py can just fetch the value of these
-    # variables. When used from setup.py, we don't want to import
-    # _version.py, so we do it with a regexp instead. This function is not
-    # used from _version.py.
-    variables = {}
+    # keywords. When used from setup.py, we don't want to import _version.py,
+    # so we do it with a regexp instead. This function is not used from
+    # _version.py.
+    keywords = {}
     try:
-        f = open(versionfile_source,"r")
+        f = open(versionfile_abs, "r")
         for line in f.readlines():
             if line.strip().startswith("git_refnames ="):
                 mo = re.search(r'=\s*"(.*)"', line)
                 if mo:
-                    variables["refnames"] = mo.group(1)
+                    keywords["refnames"] = mo.group(1)
             if line.strip().startswith("git_full ="):
                 mo = re.search(r'=\s*"(.*)"', line)
                 if mo:
-                    variables["full"] = mo.group(1)
+                    keywords["full"] = mo.group(1)
         f.close()
     except EnvironmentError:
         pass
-    return variables
+    return keywords
+
 
-def versions_from_expanded_variables(variables, tag_prefix, verbose=False):
-    refnames = variables["refnames"].strip()
+@register_vcs_handler("git", "keywords")
+def git_versions_from_keywords(keywords, tag_prefix, verbose):
+    """Get version information from git keywords."""
+    if not keywords:
+        raise NotThisMethod("no keywords at all, weird")
+    refnames = keywords["refnames"].strip()
     if refnames.startswith("$Format"):
         if verbose:
-            print("variables are unexpanded, not using")
-        return {} # unexpanded, so not in an unpacked git-archive tarball
+            print("keywords are unexpanded, not using")
+        raise NotThisMethod("unexpanded keywords, not a git-archive tarball")
     refs = set([r.strip() for r in refnames.strip("()").split(",")])
     # starting in git-1.8.3, tags are listed as "tag: foo-1.0" instead of
     # just "foo-1.0". If we see a "tag: " prefix, prefer those.
@@ -189,172 +660,350 @@ def versions_from_expanded_variables(variables, tag_prefix, verbose=False):
             r = ref[len(tag_prefix):]
             if verbose:
                 print("picking %%s" %% r)
-            return { "version": r,
-                     "full": variables["full"].strip() }
-    # no suitable tags, so we use the full revision id
+            return {"version": r,
+                    "full-revisionid": keywords["full"].strip(),
+                    "dirty": False, "error": None
+                    }
+    # no suitable tags, so version is "0+unknown", but full hex is still there
     if verbose:
-        print("no suitable tags, using full revision id")
-    return { "version": variables["full"].strip(),
-             "full": variables["full"].strip() }
-
-def versions_from_vcs(tag_prefix, versionfile_source, verbose=False):
-    # this runs 'git' from the root of the source tree. That either means
-    # someone ran a setup.py command (and this code is in versioneer.py, so
-    # IN_LONG_VERSION_PY=False, thus the containing directory is the root of
-    # the source tree), or someone ran a project-specific entry point (and
-    # this code is in _version.py, so IN_LONG_VERSION_PY=True, thus the
-    # containing directory is somewhere deeper in the source tree). This only
-    # gets called if the git-archive 'subst' variables were *not* expanded,
-    # and _version.py hasn't already been rewritten with a short version
-    # string, meaning we're inside a checked out source tree.
+        print("no suitable tags, using unknown + full revision id")
+    return {"version": "0+unknown",
+            "full-revisionid": keywords["full"].strip(),
+            "dirty": False, "error": "no suitable tags"}
 
-    try:
-        here = os.path.abspath(__file__)
-    except NameError:
-        # some py2exe/bbfreeze/non-CPython implementations don't do __file__
-        return {} # not always correct
-
-    # versionfile_source is the relative path from the top of the source tree
-    # (where the .git directory might live) to this file. Invert this to find
-    # the root from __file__.
-    root = here
-    if IN_LONG_VERSION_PY:
-        for i in range(len(versionfile_source.split("/"))):
-            root = os.path.dirname(root)
-    else:
-        root = os.path.dirname(here)
+
+@register_vcs_handler("git", "pieces_from_vcs")
+def git_pieces_from_vcs(tag_prefix, root, verbose, run_command=run_command):
+    """Get version from 'git describe' in the root of the source tree.
+
+    This only gets called if the git-archive 'subst' keywords were *not*
+    expanded, and _version.py hasn't already been rewritten with a short
+    version string, meaning we're inside a checked out source tree.
+    """
     if not os.path.exists(os.path.join(root, ".git")):
         if verbose:
             print("no .git in %%s" %% root)
-        return {}
+        raise NotThisMethod("no .git directory")
 
-    GIT = "git"
+    GITS = ["git"]
     if sys.platform == "win32":
-        GIT = "git.exe"
-    stdout = run_command([GIT, "describe", "--tags", "--dirty", "--always"],
-                         cwd=root)
-    if stdout is None:
-        return {}
-    if not stdout.startswith(tag_prefix):
-        if verbose:
-            print("tag '%%s' doesn't start with prefix '%%s'" %% (stdout, tag_prefix))
-        return {}
-    tag = stdout[len(tag_prefix):]
-    stdout = run_command([GIT, "rev-parse", "HEAD"], cwd=root)
-    if stdout is None:
-        return {}
-    full = stdout.strip()
-    if tag.endswith("-dirty"):
-        full += "-dirty"
-    return {"version": tag, "full": full}
-
-
-def versions_from_parentdir(parentdir_prefix, versionfile_source, verbose=False):
-    if IN_LONG_VERSION_PY:
-        # We're running from _version.py. If it's from a source tree
-        # (execute-in-place), we can work upwards to find the root of the
-        # tree, and then check the parent directory for a version string. If
-        # it's in an installed application, there's no hope.
-        try:
-            here = os.path.abspath(__file__)
-        except NameError:
-            # py2exe/bbfreeze/non-CPython don't have __file__
-            return {} # without __file__, we have no hope
-        # versionfile_source is the relative path from the top of the source
-        # tree to _version.py. Invert this to find the root from __file__.
-        root = here
-        for i in range(len(versionfile_source.split("/"))):
-            root = os.path.dirname(root)
+        GITS = ["git.cmd", "git.exe"]
+    # if there is a tag matching tag_prefix, this yields TAG-NUM-gHEX[-dirty]
+    # if there isn't one, this yields HEX[-dirty] (no NUM)
+    describe_out = run_command(GITS, ["describe", "--tags", "--dirty",
+                                      "--always", "--long",
+                                      "--match", "%%s*" %% tag_prefix],
+                               cwd=root)
+    # --long was added in git-1.5.5
+    if describe_out is None:
+        raise NotThisMethod("'git describe' failed")
+    describe_out = describe_out.strip()
+    full_out = run_command(GITS, ["rev-parse", "HEAD"], cwd=root)
+    if full_out is None:
+        raise NotThisMethod("'git rev-parse' failed")
+    full_out = full_out.strip()
+
+    pieces = {}
+    pieces["long"] = full_out
+    pieces["short"] = full_out[:7]  # maybe improved later
+    pieces["error"] = None
+
+    # parse describe_out. It will be like TAG-NUM-gHEX[-dirty] or HEX[-dirty]
+    # TAG might have hyphens.
+    git_describe = describe_out
+
+    # look for -dirty suffix
+    dirty = git_describe.endswith("-dirty")
+    pieces["dirty"] = dirty
+    if dirty:
+        git_describe = git_describe[:git_describe.rindex("-dirty")]
+
+    # now we have TAG-NUM-gHEX or HEX
+
+    if "-" in git_describe:
+        # TAG-NUM-gHEX
+        mo = re.search(r'^(.+)-(\d+)-g([0-9a-f]+)$', git_describe)
+        if not mo:
+            # unparseable. Maybe git-describe is misbehaving?
+            pieces["error"] = ("unable to parse git-describe output: '%%s'"
+                               %% describe_out)
+            return pieces
+
+        # tag
+        full_tag = mo.group(1)
+        if not full_tag.startswith(tag_prefix):
+            if verbose:
+                fmt = "tag '%%s' doesn't start with prefix '%%s'"
+                print(fmt %% (full_tag, tag_prefix))
+            pieces["error"] = ("tag '%%s' doesn't start with prefix '%%s'"
+                               %% (full_tag, tag_prefix))
+            return pieces
+        pieces["closest-tag"] = full_tag[len(tag_prefix):]
+
+        # distance: number of commits since tag
+        pieces["distance"] = int(mo.group(2))
+
+        # commit: short hex revision ID
+        pieces["short"] = mo.group(3)
+
+    else:
+        # HEX: no tags
+        pieces["closest-tag"] = None
+        count_out = run_command(GITS, ["rev-list", "HEAD", "--count"],
+                                cwd=root)
+        pieces["distance"] = int(count_out)  # total number of commits
+
+    return pieces
+
+
+def plus_or_dot(pieces):
+    """Return a + if we don't already have one, else return a ."""
+    if "+" in pieces.get("closest-tag", ""):
+        return "."
+    return "+"
+
+
+def render_pep440(pieces):
+    """Build up version string, with post-release "local version identifier".
+
+    Our goal: TAG[+DISTANCE.gHEX[.dirty]] . Note that if you
+    get a tagged build and then dirty it, you'll get TAG+0.gHEX.dirty
+
+    Exceptions:
+    1: no tags. git_describe was just HEX. 0+untagged.DISTANCE.gHEX[.dirty]
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        if pieces["distance"] or pieces["dirty"]:
+            rendered += plus_or_dot(pieces)
+            rendered += "%%d.g%%s" %% (pieces["distance"], pieces["short"])
+            if pieces["dirty"]:
+                rendered += ".dirty"
+    else:
+        # exception #1
+        rendered = "0+untagged.%%d.g%%s" %% (pieces["distance"],
+                                          pieces["short"])
+        if pieces["dirty"]:
+            rendered += ".dirty"
+    return rendered
+
+
+def render_pep440_pre(pieces):
+    """TAG[.post.devDISTANCE] -- No -dirty.
+
+    Exceptions:
+    1: no tags. 0.post.devDISTANCE
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        if pieces["distance"]:
+            rendered += ".post.dev%%d" %% pieces["distance"]
     else:
-        # we're running from versioneer.py, which means we're running from
-        # the setup.py in a source tree. sys.argv[0] is setup.py in the root.
-        here = os.path.abspath(sys.argv[0])
-        root = os.path.dirname(here)
+        # exception #1
+        rendered = "0.post.dev%%d" %% pieces["distance"]
+    return rendered
+
+
+def render_pep440_post(pieces):
+    """TAG[.postDISTANCE[.dev0]+gHEX] .
+
+    The ".dev0" means dirty. Note that .dev0 sorts backwards
+    (a dirty tree will appear "older" than the corresponding clean one),
+    but you shouldn't be releasing software with -dirty anyways.
+
+    Exceptions:
+    1: no tags. 0.postDISTANCE[.dev0]
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        if pieces["distance"] or pieces["dirty"]:
+            rendered += ".post%%d" %% pieces["distance"]
+            if pieces["dirty"]:
+                rendered += ".dev0"
+            rendered += plus_or_dot(pieces)
+            rendered += "g%%s" %% pieces["short"]
+    else:
+        # exception #1
+        rendered = "0.post%%d" %% pieces["distance"]
+        if pieces["dirty"]:
+            rendered += ".dev0"
+        rendered += "+g%%s" %% pieces["short"]
+    return rendered
+
+
+def render_pep440_old(pieces):
+    """TAG[.postDISTANCE[.dev0]] .
+
+    The ".dev0" means dirty.
+
+    Eexceptions:
+    1: no tags. 0.postDISTANCE[.dev0]
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        if pieces["distance"] or pieces["dirty"]:
+            rendered += ".post%%d" %% pieces["distance"]
+            if pieces["dirty"]:
+                rendered += ".dev0"
+    else:
+        # exception #1
+        rendered = "0.post%%d" %% pieces["distance"]
+        if pieces["dirty"]:
+            rendered += ".dev0"
+    return rendered
 
-    # Source tarballs conventionally unpack into a directory that includes
-    # both the project name and a version string.
-    dirname = os.path.basename(root)
-    if not dirname.startswith(parentdir_prefix):
-        if verbose:
-            print("guessing rootdir is '%%s', but '%%s' doesn't start with prefix '%%s'" %%
-                  (root, dirname, parentdir_prefix))
-        return None
-    return {"version": dirname[len(parentdir_prefix):], "full": ""}
-
-tag_prefix = "%(TAG_PREFIX)s"
-parentdir_prefix = "%(PARENTDIR_PREFIX)s"
-versionfile_source = "%(VERSIONFILE_SOURCE)s"
-
-def get_versions(default={"version": "unknown", "full": ""}, verbose=False):
-    variables = { "refnames": git_refnames, "full": git_full }
-    ver = versions_from_expanded_variables(variables, tag_prefix, verbose)
-    if not ver:
-        ver = versions_from_vcs(tag_prefix, versionfile_source, verbose)
-    if not ver:
-        ver = versions_from_parentdir(parentdir_prefix, versionfile_source,
-                                      verbose)
-    if not ver:
-        ver = default
-    return ver
 
-'''
+def render_git_describe(pieces):
+    """TAG[-DISTANCE-gHEX][-dirty].
 
+    Like 'git describe --tags --dirty --always'.
 
-import subprocess
-import sys
+    Exceptions:
+    1: no tags. HEX[-dirty]  (note: no 'g' prefix)
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        if pieces["distance"]:
+            rendered += "-%%d-g%%s" %% (pieces["distance"], pieces["short"])
+    else:
+        # exception #1
+        rendered = pieces["short"]
+    if pieces["dirty"]:
+        rendered += "-dirty"
+    return rendered
+
+
+def render_git_describe_long(pieces):
+    """TAG-DISTANCE-gHEX[-dirty].
+
+    Like 'git describe --tags --dirty --always -long'.
+    The distance/hash is unconditional.
+
+    Exceptions:
+    1: no tags. HEX[-dirty]  (note: no 'g' prefix)
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        rendered += "-%%d-g%%s" %% (pieces["distance"], pieces["short"])
+    else:
+        # exception #1
+        rendered = pieces["short"]
+    if pieces["dirty"]:
+        rendered += "-dirty"
+    return rendered
+
+
+def render(pieces, style):
+    """Render the given version pieces into the requested style."""
+    if pieces["error"]:
+        return {"version": "unknown",
+                "full-revisionid": pieces.get("long"),
+                "dirty": None,
+                "error": pieces["error"]}
+
+    if not style or style == "default":
+        style = "pep440"  # the default
+
+    if style == "pep440":
+        rendered = render_pep440(pieces)
+    elif style == "pep440-pre":
+        rendered = render_pep440_pre(pieces)
+    elif style == "pep440-post":
+        rendered = render_pep440_post(pieces)
+    elif style == "pep440-old":
+        rendered = render_pep440_old(pieces)
+    elif style == "git-describe":
+        rendered = render_git_describe(pieces)
+    elif style == "git-describe-long":
+        rendered = render_git_describe_long(pieces)
+    else:
+        raise ValueError("unknown style '%%s'" %% style)
+
+    return {"version": rendered, "full-revisionid": pieces["long"],
+            "dirty": pieces["dirty"], "error": None}
+
+
+def get_versions():
+    """Get version information or return default if unable to do so."""
+    # I am in _version.py, which lives at ROOT/VERSIONFILE_SOURCE. If we have
+    # __file__, we can work backwards from there to the root. Some
+    # py2exe/bbfreeze/non-CPython implementations don't do __file__, in which
+    # case we can only use expanded keywords.
+
+    cfg = get_config()
+    verbose = cfg.verbose
 
-def run_command(args, cwd=None, verbose=False):
     try:
-        # remember shell=False, so use git.exe on windows, not just git
-        p = subprocess.Popen(args, stdout=subprocess.PIPE, cwd=cwd)
-    except EnvironmentError:
-        e = sys.exc_info()[1]
-        if verbose:
-            print("unable to run %s" % args[0])
-            print(e)
-        return None
-    stdout = p.communicate()[0].strip()
-    if sys.version >= '3':
-        stdout = stdout.decode()
-    if p.returncode != 0:
-        if verbose:
-            print("unable to run %s (error)" % args[0])
-        return None
-    return stdout
+        return git_versions_from_keywords(get_keywords(), cfg.tag_prefix,
+                                          verbose)
+    except NotThisMethod:
+        pass
 
+    try:
+        root = os.path.realpath(__file__)
+        # versionfile_source is the relative path from the top of the source
+        # tree (where the .git directory might live) to this file. Invert
+        # this to find the root from __file__.
+        for i in cfg.versionfile_source.split('/'):
+            root = os.path.dirname(root)
+    except NameError:
+        return {"version": "0+unknown", "full-revisionid": None,
+                "dirty": None,
+                "error": "unable to find root of source tree"}
 
-import sys
-import re
-import os.path
+    try:
+        pieces = git_pieces_from_vcs(cfg.tag_prefix, root, verbose)
+        return render(pieces, cfg.style)
+    except NotThisMethod:
+        pass
+
+    try:
+        if cfg.parentdir_prefix:
+            return versions_from_parentdir(cfg.parentdir_prefix, root, verbose)
+    except NotThisMethod:
+        pass
 
-def get_expanded_variables(versionfile_source):
+    return {"version": "0+unknown", "full-revisionid": None,
+            "dirty": None,
+            "error": "unable to compute version"}
+'''
+
+
+@register_vcs_handler("git", "get_keywords")
+def git_get_keywords(versionfile_abs):
+    """Extract version information from the given file."""
     # the code embedded in _version.py can just fetch the value of these
-    # variables. When used from setup.py, we don't want to import
-    # _version.py, so we do it with a regexp instead. This function is not
-    # used from _version.py.
-    variables = {}
+    # keywords. When used from setup.py, we don't want to import _version.py,
+    # so we do it with a regexp instead. This function is not used from
+    # _version.py.
+    keywords = {}
     try:
-        f = open(versionfile_source,"r")
+        f = open(versionfile_abs, "r")
         for line in f.readlines():
             if line.strip().startswith("git_refnames ="):
                 mo = re.search(r'=\s*"(.*)"', line)
                 if mo:
-                    variables["refnames"] = mo.group(1)
+                    keywords["refnames"] = mo.group(1)
             if line.strip().startswith("git_full ="):
                 mo = re.search(r'=\s*"(.*)"', line)
                 if mo:
-                    variables["full"] = mo.group(1)
+                    keywords["full"] = mo.group(1)
         f.close()
     except EnvironmentError:
         pass
-    return variables
+    return keywords
+
 
-def versions_from_expanded_variables(variables, tag_prefix, verbose=False):
-    refnames = variables["refnames"].strip()
+@register_vcs_handler("git", "keywords")
+def git_versions_from_keywords(keywords, tag_prefix, verbose):
+    """Get version information from git keywords."""
+    if not keywords:
+        raise NotThisMethod("no keywords at all, weird")
+    refnames = keywords["refnames"].strip()
     if refnames.startswith("$Format"):
         if verbose:
-            print("variables are unexpanded, not using")
-        return {} # unexpanded, so not in an unpacked git-archive tarball
+            print("keywords are unexpanded, not using")
+        raise NotThisMethod("unexpanded keywords, not a git-archive tarball")
     refs = set([r.strip() for r in refnames.strip("()").split(",")])
     # starting in git-1.8.3, tags are listed as "tag: foo-1.0" instead of
     # just "foo-1.0". If we see a "tag: " prefix, prefer those.
@@ -379,107 +1028,122 @@ def versions_from_expanded_variables(variables, tag_prefix, verbose=False):
             r = ref[len(tag_prefix):]
             if verbose:
                 print("picking %s" % r)
-            return { "version": r,
-                     "full": variables["full"].strip() }
-    # no suitable tags, so we use the full revision id
+            return {"version": r,
+                    "full-revisionid": keywords["full"].strip(),
+                    "dirty": False, "error": None
+                    }
+    # no suitable tags, so version is "0+unknown", but full hex is still there
     if verbose:
-        print("no suitable tags, using full revision id")
-    return { "version": variables["full"].strip(),
-             "full": variables["full"].strip() }
-
-def versions_from_vcs(tag_prefix, versionfile_source, verbose=False):
-    # this runs 'git' from the root of the source tree. That either means
-    # someone ran a setup.py command (and this code is in versioneer.py, so
-    # IN_LONG_VERSION_PY=False, thus the containing directory is the root of
-    # the source tree), or someone ran a project-specific entry point (and
-    # this code is in _version.py, so IN_LONG_VERSION_PY=True, thus the
-    # containing directory is somewhere deeper in the source tree). This only
-    # gets called if the git-archive 'subst' variables were *not* expanded,
-    # and _version.py hasn't already been rewritten with a short version
-    # string, meaning we're inside a checked out source tree.
+        print("no suitable tags, using unknown + full revision id")
+    return {"version": "0+unknown",
+            "full-revisionid": keywords["full"].strip(),
+            "dirty": False, "error": "no suitable tags"}
 
-    try:
-        here = os.path.abspath(__file__)
-    except NameError:
-        # some py2exe/bbfreeze/non-CPython implementations don't do __file__
-        return {} # not always correct
-
-    # versionfile_source is the relative path from the top of the source tree
-    # (where the .git directory might live) to this file. Invert this to find
-    # the root from __file__.
-    root = here
-    if IN_LONG_VERSION_PY:
-        for i in range(len(versionfile_source.split("/"))):
-            root = os.path.dirname(root)
-    else:
-        root = os.path.dirname(here)
+
+@register_vcs_handler("git", "pieces_from_vcs")
+def git_pieces_from_vcs(tag_prefix, root, verbose, run_command=run_command):
+    """Get version from 'git describe' in the root of the source tree.
+
+    This only gets called if the git-archive 'subst' keywords were *not*
+    expanded, and _version.py hasn't already been rewritten with a short
+    version string, meaning we're inside a checked out source tree.
+    """
     if not os.path.exists(os.path.join(root, ".git")):
         if verbose:
             print("no .git in %s" % root)
-        return {}
+        raise NotThisMethod("no .git directory")
 
-    GIT = "git"
+    GITS = ["git"]
     if sys.platform == "win32":
-        GIT = "git.exe"
-    stdout = run_command([GIT, "describe", "--tags", "--dirty", "--always"],
-                         cwd=root)
-    if stdout is None:
-        return {}
-    if not stdout.startswith(tag_prefix):
-        if verbose:
-            print("tag '%s' doesn't start with prefix '%s'" % (stdout, tag_prefix))
-        return {}
-    tag = stdout[len(tag_prefix):]
-    stdout = run_command([GIT, "rev-parse", "HEAD"], cwd=root)
-    if stdout is None:
-        return {}
-    full = stdout.strip()
-    if tag.endswith("-dirty"):
-        full += "-dirty"
-    return {"version": tag, "full": full}
-
-
-def versions_from_parentdir(parentdir_prefix, versionfile_source, verbose=False):
-    if IN_LONG_VERSION_PY:
-        # We're running from _version.py. If it's from a source tree
-        # (execute-in-place), we can work upwards to find the root of the
-        # tree, and then check the parent directory for a version string. If
-        # it's in an installed application, there's no hope.
-        try:
-            here = os.path.abspath(__file__)
-        except NameError:
-            # py2exe/bbfreeze/non-CPython don't have __file__
-            return {} # without __file__, we have no hope
-        # versionfile_source is the relative path from the top of the source
-        # tree to _version.py. Invert this to find the root from __file__.
-        root = here
-        for i in range(len(versionfile_source.split("/"))):
-            root = os.path.dirname(root)
+        GITS = ["git.cmd", "git.exe"]
+    # if there is a tag matching tag_prefix, this yields TAG-NUM-gHEX[-dirty]
+    # if there isn't one, this yields HEX[-dirty] (no NUM)
+    describe_out = run_command(GITS, ["describe", "--tags", "--dirty",
+                                      "--always", "--long",
+                                      "--match", "%s*" % tag_prefix],
+                               cwd=root)
+    # --long was added in git-1.5.5
+    if describe_out is None:
+        raise NotThisMethod("'git describe' failed")
+    describe_out = describe_out.strip()
+    full_out = run_command(GITS, ["rev-parse", "HEAD"], cwd=root)
+    if full_out is None:
+        raise NotThisMethod("'git rev-parse' failed")
+    full_out = full_out.strip()
+
+    pieces = {}
+    pieces["long"] = full_out
+    pieces["short"] = full_out[:7]  # maybe improved later
+    pieces["error"] = None
+
+    # parse describe_out. It will be like TAG-NUM-gHEX[-dirty] or HEX[-dirty]
+    # TAG might have hyphens.
+    git_describe = describe_out
+
+    # look for -dirty suffix
+    dirty = git_describe.endswith("-dirty")
+    pieces["dirty"] = dirty
+    if dirty:
+        git_describe = git_describe[:git_describe.rindex("-dirty")]
+
+    # now we have TAG-NUM-gHEX or HEX
+
+    if "-" in git_describe:
+        # TAG-NUM-gHEX
+        mo = re.search(r'^(.+)-(\d+)-g([0-9a-f]+)$', git_describe)
+        if not mo:
+            # unparseable. Maybe git-describe is misbehaving?
+            pieces["error"] = ("unable to parse git-describe output: '%s'"
+                               % describe_out)
+            return pieces
+
+        # tag
+        full_tag = mo.group(1)
+        if not full_tag.startswith(tag_prefix):
+            if verbose:
+                fmt = "tag '%s' doesn't start with prefix '%s'"
+                print(fmt % (full_tag, tag_prefix))
+            pieces["error"] = ("tag '%s' doesn't start with prefix '%s'"
+                               % (full_tag, tag_prefix))
+            return pieces
+        pieces["closest-tag"] = full_tag[len(tag_prefix):]
+
+        # distance: number of commits since tag
+        pieces["distance"] = int(mo.group(2))
+
+        # commit: short hex revision ID
+        pieces["short"] = mo.group(3)
+
     else:
-        # we're running from versioneer.py, which means we're running from
-        # the setup.py in a source tree. sys.argv[0] is setup.py in the root.
-        here = os.path.abspath(sys.argv[0])
-        root = os.path.dirname(here)
+        # HEX: no tags
+        pieces["closest-tag"] = None
+        count_out = run_command(GITS, ["rev-list", "HEAD", "--count"],
+                                cwd=root)
+        pieces["distance"] = int(count_out)  # total number of commits
 
-    # Source tarballs conventionally unpack into a directory that includes
-    # both the project name and a version string.
-    dirname = os.path.basename(root)
-    if not dirname.startswith(parentdir_prefix):
-        if verbose:
-            print("guessing rootdir is '%s', but '%s' doesn't start with prefix '%s'" %
-                  (root, dirname, parentdir_prefix))
-        return None
-    return {"version": dirname[len(parentdir_prefix):], "full": ""}
+    return pieces
 
-import sys
 
-def do_vcs_install(versionfile_source, ipy):
-    GIT = "git"
+def do_vcs_install(manifest_in, versionfile_source, ipy):
+    """Git-specific installation logic for Versioneer.
+
+    For Git, this means creating/changing .gitattributes to mark _version.py
+    for export-time keyword substitution.
+    """
+    GITS = ["git"]
     if sys.platform == "win32":
-        GIT = "git.exe"
-    run_command([GIT, "add", "versioneer.py"])
-    run_command([GIT, "add", versionfile_source])
-    run_command([GIT, "add", ipy])
+        GITS = ["git.cmd", "git.exe"]
+    files = [manifest_in, versionfile_source]
+    if ipy:
+        files.append(ipy)
+    try:
+        me = __file__
+        if me.endswith(".pyc") or me.endswith(".pyo"):
+            me = os.path.splitext(me)[0] + ".py"
+        versioneer_file = os.path.relpath(me)
+    except NameError:
+        versioneer_file = "versioneer.py"
+    files.append(versioneer_file)
     present = False
     try:
         f = open(".gitattributes", "r")
@@ -494,135 +1158,487 @@ def do_vcs_install(versionfile_source, ipy):
         f = open(".gitattributes", "a+")
         f.write("%s export-subst\n" % versionfile_source)
         f.close()
-        run_command([GIT, "add", ".gitattributes"])
+        files.append(".gitattributes")
+    run_command(GITS, ["add", "--"] + files)
+
 
+def versions_from_parentdir(parentdir_prefix, root, verbose):
+    """Try to determine the version from the parent directory name.
+
+    Source tarballs conventionally unpack into a directory that includes
+    both the project name and a version string.
+    """
+    dirname = os.path.basename(root)
+    if not dirname.startswith(parentdir_prefix):
+        if verbose:
+            print("guessing rootdir is '%s', but '%s' doesn't start with "
+                  "prefix '%s'" % (root, dirname, parentdir_prefix))
+        raise NotThisMethod("rootdir doesn't start with parentdir_prefix")
+    return {"version": dirname[len(parentdir_prefix):],
+            "full-revisionid": None,
+            "dirty": False, "error": None}
 
 SHORT_VERSION_PY = """
-# This file was generated by 'versioneer.py' (0.7+) from
+# This file was generated by 'versioneer.py' (0.16) from
 # revision-control system data, or from the parent directory name of an
 # unpacked source archive. Distribution tarballs contain a pre-generated copy
 # of this file.
 
-version_version = '%(version)s'
-version_full = '%(full)s'
-def get_versions(default={}, verbose=False):
-    return {'version': version_version, 'full': version_full}
+import json
+import sys
+
+version_json = '''
+%s
+'''  # END VERSION_JSON
 
+
+def get_versions():
+    return json.loads(version_json)
 """
 
-DEFAULT = {"version": "unknown", "full": "unknown"}
 
 def versions_from_file(filename):
-    versions = {}
+    """Try to determine the version from _version.py if present."""
     try:
-        f = open(filename)
+        with open(filename) as f:
+            contents = f.read()
     except EnvironmentError:
-        return versions
-    for line in f.readlines():
-        mo = re.match("version_version = '([^']+)'", line)
-        if mo:
-            versions["version"] = mo.group(1)
-        mo = re.match("version_full = '([^']+)'", line)
-        if mo:
-            versions["full"] = mo.group(1)
-    f.close()
-    return versions
+        raise NotThisMethod("unable to read _version.py")
+    mo = re.search(r"version_json = '''\n(.*)'''  # END VERSION_JSON",
+                   contents, re.M | re.S)
+    if not mo:
+        raise NotThisMethod("no version_json in _version.py")
+    return json.loads(mo.group(1))
+
 
 def write_to_version_file(filename, versions):
-    f = open(filename, "w")
-    f.write(SHORT_VERSION_PY % versions)
-    f.close()
+    """Write the given version number to the given _version.py file."""
+    os.unlink(filename)
+    contents = json.dumps(versions, sort_keys=True,
+                          indent=1, separators=(",", ": "))
+    with open(filename, "w") as f:
+        f.write(SHORT_VERSION_PY % contents)
+
     print("set %s to '%s'" % (filename, versions["version"]))
 
 
-def get_best_versions(versionfile, tag_prefix, parentdir_prefix,
-                      default=DEFAULT, verbose=False):
-    # returns dict with two keys: 'version' and 'full'
-    #
-    # extract version from first of _version.py, 'git describe', parentdir.
-    # This is meant to work for developers using a source checkout, for users
-    # of a tarball created by 'setup.py sdist', and for users of a
-    # tarball/zipball created by 'git archive' or github's download-from-tag
-    # feature.
-
-    variables = get_expanded_variables(versionfile_source)
-    if variables:
-        ver = versions_from_expanded_variables(variables, tag_prefix)
-        if ver:
-            if verbose: print("got version from expanded variable %s" % ver)
-            return ver
+def plus_or_dot(pieces):
+    """Return a + if we don't already have one, else return a ."""
+    if "+" in pieces.get("closest-tag", ""):
+        return "."
+    return "+"
 
-    ver = versions_from_file(versionfile)
-    if ver:
-        if verbose: print("got version from file %s %s" % (versionfile, ver))
-        return ver
 
-    ver = versions_from_vcs(tag_prefix, versionfile_source, verbose)
-    if ver:
-        if verbose: print("got version from git %s" % ver)
-        return ver
+def render_pep440(pieces):
+    """Build up version string, with post-release "local version identifier".
 
-    ver = versions_from_parentdir(parentdir_prefix, versionfile_source, verbose)
-    if ver:
-        if verbose: print("got version from parentdir %s" % ver)
-        return ver
+    Our goal: TAG[+DISTANCE.gHEX[.dirty]] . Note that if you
+    get a tagged build and then dirty it, you'll get TAG+0.gHEX.dirty
+
+    Exceptions:
+    1: no tags. git_describe was just HEX. 0+untagged.DISTANCE.gHEX[.dirty]
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        if pieces["distance"] or pieces["dirty"]:
+            rendered += plus_or_dot(pieces)
+            rendered += "%d.g%s" % (pieces["distance"], pieces["short"])
+            if pieces["dirty"]:
+                rendered += ".dirty"
+    else:
+        # exception #1
+        rendered = "0+untagged.%d.g%s" % (pieces["distance"],
+                                          pieces["short"])
+        if pieces["dirty"]:
+            rendered += ".dirty"
+    return rendered
+
+
+def render_pep440_pre(pieces):
+    """TAG[.post.devDISTANCE] -- No -dirty.
+
+    Exceptions:
+    1: no tags. 0.post.devDISTANCE
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        if pieces["distance"]:
+            rendered += ".post.dev%d" % pieces["distance"]
+    else:
+        # exception #1
+        rendered = "0.post.dev%d" % pieces["distance"]
+    return rendered
+
+
+def render_pep440_post(pieces):
+    """TAG[.postDISTANCE[.dev0]+gHEX] .
+
+    The ".dev0" means dirty. Note that .dev0 sorts backwards
+    (a dirty tree will appear "older" than the corresponding clean one),
+    but you shouldn't be releasing software with -dirty anyways.
+
+    Exceptions:
+    1: no tags. 0.postDISTANCE[.dev0]
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        if pieces["distance"] or pieces["dirty"]:
+            rendered += ".post%d" % pieces["distance"]
+            if pieces["dirty"]:
+                rendered += ".dev0"
+            rendered += plus_or_dot(pieces)
+            rendered += "g%s" % pieces["short"]
+    else:
+        # exception #1
+        rendered = "0.post%d" % pieces["distance"]
+        if pieces["dirty"]:
+            rendered += ".dev0"
+        rendered += "+g%s" % pieces["short"]
+    return rendered
+
+
+def render_pep440_old(pieces):
+    """TAG[.postDISTANCE[.dev0]] .
+
+    The ".dev0" means dirty.
+
+    Eexceptions:
+    1: no tags. 0.postDISTANCE[.dev0]
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        if pieces["distance"] or pieces["dirty"]:
+            rendered += ".post%d" % pieces["distance"]
+            if pieces["dirty"]:
+                rendered += ".dev0"
+    else:
+        # exception #1
+        rendered = "0.post%d" % pieces["distance"]
+        if pieces["dirty"]:
+            rendered += ".dev0"
+    return rendered
+
+
+def render_git_describe(pieces):
+    """TAG[-DISTANCE-gHEX][-dirty].
+
+    Like 'git describe --tags --dirty --always'.
 
-    if verbose: print("got version from default %s" % ver)
-    return default
-
-def get_versions(default=DEFAULT, verbose=False):
-    assert versionfile_source is not None, "please set versioneer.versionfile_source"
-    assert tag_prefix is not None, "please set versioneer.tag_prefix"
-    assert parentdir_prefix is not None, "please set versioneer.parentdir_prefix"
-    return get_best_versions(versionfile_source, tag_prefix, parentdir_prefix,
-                             default=default, verbose=verbose)
-def get_version(verbose=False):
-    return get_versions(verbose=verbose)["version"]
-
-class cmd_version(Command):
-    description = "report generated version string"
-    user_options = []
-    boolean_options = []
-    def initialize_options(self):
+    Exceptions:
+    1: no tags. HEX[-dirty]  (note: no 'g' prefix)
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        if pieces["distance"]:
+            rendered += "-%d-g%s" % (pieces["distance"], pieces["short"])
+    else:
+        # exception #1
+        rendered = pieces["short"]
+    if pieces["dirty"]:
+        rendered += "-dirty"
+    return rendered
+
+
+def render_git_describe_long(pieces):
+    """TAG-DISTANCE-gHEX[-dirty].
+
+    Like 'git describe --tags --dirty --always -long'.
+    The distance/hash is unconditional.
+
+    Exceptions:
+    1: no tags. HEX[-dirty]  (note: no 'g' prefix)
+    """
+    if pieces["closest-tag"]:
+        rendered = pieces["closest-tag"]
+        rendered += "-%d-g%s" % (pieces["distance"], pieces["short"])
+    else:
+        # exception #1
+        rendered = pieces["short"]
+    if pieces["dirty"]:
+        rendered += "-dirty"
+    return rendered
+
+
+def render(pieces, style):
+    """Render the given version pieces into the requested style."""
+    if pieces["error"]:
+        return {"version": "unknown",
+                "full-revisionid": pieces.get("long"),
+                "dirty": None,
+                "error": pieces["error"]}
+
+    if not style or style == "default":
+        style = "pep440"  # the default
+
+    if style == "pep440":
+        rendered = render_pep440(pieces)
+    elif style == "pep440-pre":
+        rendered = render_pep440_pre(pieces)
+    elif style == "pep440-post":
+        rendered = render_pep440_post(pieces)
+    elif style == "pep440-old":
+        rendered = render_pep440_old(pieces)
+    elif style == "git-describe":
+        rendered = render_git_describe(pieces)
+    elif style == "git-describe-long":
+        rendered = render_git_describe_long(pieces)
+    else:
+        raise ValueError("unknown style '%s'" % style)
+
+    return {"version": rendered, "full-revisionid": pieces["long"],
+            "dirty": pieces["dirty"], "error": None}
+
+
+class VersioneerBadRootError(Exception):
+    """The project root directory is unknown or missing key files."""
+
+
+def get_versions(verbose=False):
+    """Get the project version from whatever source is available.
+
+    Returns dict with two keys: 'version' and 'full'.
+    """
+    if "versioneer" in sys.modules:
+        # see the discussion in cmdclass.py:get_cmdclass()
+        del sys.modules["versioneer"]
+
+    root = get_root()
+    cfg = get_config_from_root(root)
+
+    assert cfg.VCS is not None, "please set [versioneer]VCS= in setup.cfg"
+    handlers = HANDLERS.get(cfg.VCS)
+    assert handlers, "unrecognized VCS '%s'" % cfg.VCS
+    verbose = verbose or cfg.verbose
+    assert cfg.versionfile_source is not None, \
+        "please set versioneer.versionfile_source"
+    assert cfg.tag_prefix is not None, "please set versioneer.tag_prefix"
+
+    versionfile_abs = os.path.join(root, cfg.versionfile_source)
+
+    # extract version from first of: _version.py, VCS command (e.g. 'git
+    # describe'), parentdir. This is meant to work for developers using a
+    # source checkout, for users of a tarball created by 'setup.py sdist',
+    # and for users of a tarball/zipball created by 'git archive' or github's
+    # download-from-tag feature or the equivalent in other VCSes.
+
+    get_keywords_f = handlers.get("get_keywords")
+    from_keywords_f = handlers.get("keywords")
+    if get_keywords_f and from_keywords_f:
+        try:
+            keywords = get_keywords_f(versionfile_abs)
+            ver = from_keywords_f(keywords, cfg.tag_prefix, verbose)
+            if verbose:
+                print("got version from expanded keyword %s" % ver)
+            return ver
+        except NotThisMethod:
+            pass
+
+    try:
+        ver = versions_from_file(versionfile_abs)
+        if verbose:
+            print("got version from file %s %s" % (versionfile_abs, ver))
+        return ver
+    except NotThisMethod:
         pass
-    def finalize_options(self):
+
+    from_vcs_f = handlers.get("pieces_from_vcs")
+    if from_vcs_f:
+        try:
+            pieces = from_vcs_f(cfg.tag_prefix, root, verbose)
+            ver = render(pieces, cfg.style)
+            if verbose:
+                print("got version from VCS %s" % ver)
+            return ver
+        except NotThisMethod:
+            pass
+
+    try:
+        if cfg.parentdir_prefix:
+            ver = versions_from_parentdir(cfg.parentdir_prefix, root, verbose)
+            if verbose:
+                print("got version from parentdir %s" % ver)
+            return ver
+    except NotThisMethod:
         pass
-    def run(self):
-        ver = get_version(verbose=True)
-        print("Version is currently: %s" % ver)
-
-
-class cmd_build(_build):
-    def run(self):
-        versions = get_versions(verbose=True)
-        _build.run(self)
-        # now locate _version.py in the new build/ directory and replace it
-        # with an updated value
-        target_versionfile = os.path.join(self.build_lib, versionfile_build)
-        print("UPDATING %s" % target_versionfile)
-        os.unlink(target_versionfile)
-        f = open(target_versionfile, "w")
-        f.write(SHORT_VERSION_PY % versions)
-        f.close()
 
-class cmd_sdist(_sdist):
-    def run(self):
-        versions = get_versions(verbose=True)
-        self._versioneer_generated_versions = versions
-        # unless we update this, the command will keep using the old version
-        self.distribution.metadata.version = versions["version"]
-        return _sdist.run(self)
-
-    def make_release_tree(self, base_dir, files):
-        _sdist.make_release_tree(self, base_dir, files)
-        # now locate _version.py in the new base_dir directory (remembering
-        # that it may be a hardlink) and replace it with an updated value
-        target_versionfile = os.path.join(base_dir, versionfile_source)
-        print("UPDATING %s" % target_versionfile)
-        os.unlink(target_versionfile)
-        f = open(target_versionfile, "w")
-        f.write(SHORT_VERSION_PY % self._versioneer_generated_versions)
-        f.close()
+    if verbose:
+        print("unable to compute version")
+
+    return {"version": "0+unknown", "full-revisionid": None,
+            "dirty": None, "error": "unable to compute version"}
+
+
+def get_version():
+    """Get the short version string for this project."""
+    return get_versions()["version"]
+
+
+def get_cmdclass():
+    """Get the custom setuptools/distutils subclasses used by Versioneer."""
+    if "versioneer" in sys.modules:
+        del sys.modules["versioneer"]
+        # this fixes the "python setup.py develop" case (also 'install' and
+        # 'easy_install .'), in which subdependencies of the main project are
+        # built (using setup.py bdist_egg) in the same python process. Assume
+        # a main project A and a dependency B, which use different versions
+        # of Versioneer. A's setup.py imports A's Versioneer, leaving it in
+        # sys.modules by the time B's setup.py is executed, causing B to run
+        # with the wrong versioneer. Setuptools wraps the sub-dep builds in a
+        # sandbox that restores sys.modules to it's pre-build state, so the
+        # parent is protected against the child's "import versioneer". By
+        # removing ourselves from sys.modules here, before the child build
+        # happens, we protect the child from the parent's versioneer too.
+        # Also see https://github.com/warner/python-versioneer/issues/52
+
+    cmds = {}
+
+    # we add "version" to both distutils and setuptools
+    from distutils.core import Command
+
+    class cmd_version(Command):
+        description = "report generated version string"
+        user_options = []
+        boolean_options = []
+
+        def initialize_options(self):
+            pass
+
+        def finalize_options(self):
+            pass
+
+        def run(self):
+            vers = get_versions(verbose=True)
+            print("Version: %s" % vers["version"])
+            print(" full-revisionid: %s" % vers.get("full-revisionid"))
+            print(" dirty: %s" % vers.get("dirty"))
+            if vers["error"]:
+                print(" error: %s" % vers["error"])
+    cmds["version"] = cmd_version
+
+    # we override "build_py" in both distutils and setuptools
+    #
+    # most invocation pathways end up running build_py:
+    #  distutils/build -> build_py
+    #  distutils/install -> distutils/build ->..
+    #  setuptools/bdist_wheel -> distutils/install ->..
+    #  setuptools/bdist_egg -> distutils/install_lib -> build_py
+    #  setuptools/install -> bdist_egg ->..
+    #  setuptools/develop -> ?
+
+    # we override different "build_py" commands for both environments
+    if "setuptools" in sys.modules:
+        from setuptools.command.build_py import build_py as _build_py
+    else:
+        from distutils.command.build_py import build_py as _build_py
+
+    class cmd_build_py(_build_py):
+        def run(self):
+            root = get_root()
+            cfg = get_config_from_root(root)
+            versions = get_versions()
+            _build_py.run(self)
+            # now locate _version.py in the new build/ directory and replace
+            # it with an updated value
+            if cfg.versionfile_build:
+                target_versionfile = os.path.join(self.build_lib,
+                                                  cfg.versionfile_build)
+                print("UPDATING %s" % target_versionfile)
+                write_to_version_file(target_versionfile, versions)
+    cmds["build_py"] = cmd_build_py
+
+    if "cx_Freeze" in sys.modules:  # cx_freeze enabled?
+        from cx_Freeze.dist import build_exe as _build_exe
+
+        class cmd_build_exe(_build_exe):
+            def run(self):
+                root = get_root()
+                cfg = get_config_from_root(root)
+                versions = get_versions()
+                target_versionfile = cfg.versionfile_source
+                print("UPDATING %s" % target_versionfile)
+                write_to_version_file(target_versionfile, versions)
+
+                _build_exe.run(self)
+                os.unlink(target_versionfile)
+                with open(cfg.versionfile_source, "w") as f:
+                    LONG = LONG_VERSION_PY[cfg.VCS]
+                    f.write(LONG %
+                            {"DOLLAR": "$",
+                             "STYLE": cfg.style,
+                             "TAG_PREFIX": cfg.tag_prefix,
+                             "PARENTDIR_PREFIX": cfg.parentdir_prefix,
+                             "VERSIONFILE_SOURCE": cfg.versionfile_source,
+                             })
+        cmds["build_exe"] = cmd_build_exe
+        del cmds["build_py"]
+
+    # we override different "sdist" commands for both environments
+    if "setuptools" in sys.modules:
+        from setuptools.command.sdist import sdist as _sdist
+    else:
+        from distutils.command.sdist import sdist as _sdist
+
+    class cmd_sdist(_sdist):
+        def run(self):
+            versions = get_versions()
+            self._versioneer_generated_versions = versions
+            # unless we update this, the command will keep using the old
+            # version
+            self.distribution.metadata.version = versions["version"]
+            return _sdist.run(self)
+
+        def make_release_tree(self, base_dir, files):
+            root = get_root()
+            cfg = get_config_from_root(root)
+            _sdist.make_release_tree(self, base_dir, files)
+            # now locate _version.py in the new base_dir directory
+            # (remembering that it may be a hardlink) and replace it with an
+            # updated value
+            target_versionfile = os.path.join(base_dir, cfg.versionfile_source)
+            print("UPDATING %s" % target_versionfile)
+            write_to_version_file(target_versionfile,
+                                  self._versioneer_generated_versions)
+    cmds["sdist"] = cmd_sdist
+
+    return cmds
+
+
+CONFIG_ERROR = """
+setup.cfg is missing the necessary Versioneer configuration. You need
+a section like:
+
+ [versioneer]
+ VCS = git
+ style = pep440
+ versionfile_source = src/myproject/_version.py
+ versionfile_build = myproject/_version.py
+ tag_prefix =
+ parentdir_prefix = myproject-
+
+You will also need to edit your setup.py to use the results:
+
+ import versioneer
+ setup(version=versioneer.get_version(),
+       cmdclass=versioneer.get_cmdclass(), ...)
+
+Please read the docstring in ./versioneer.py for configuration instructions,
+edit setup.cfg, and re-run the installer or 'python versioneer.py setup'.
+"""
+
+SAMPLE_CONFIG = """
+# See the docstring in versioneer.py for instructions. Note that you must
+# re-run 'versioneer.py setup' after changing this section, and commit the
+# resulting files.
+
+[versioneer]
+#VCS = git
+#style = pep440
+#versionfile_source =
+#versionfile_build =
+#tag_prefix =
+#parentdir_prefix =
+
+"""
 
 INIT_PY_SNIPPET = """
 from ._version import get_versions
@@ -630,40 +1646,129 @@ __version__ = get_versions()['version']
 del get_versions
 """
 
-class cmd_update_files(Command):
-    description = "modify __init__.py and create _version.py"
-    user_options = []
-    boolean_options = []
-    def initialize_options(self):
-        pass
-    def finalize_options(self):
-        pass
-    def run(self):
-        ipy = os.path.join(os.path.dirname(versionfile_source), "__init__.py")
-        print(" creating %s" % versionfile_source)
-        f = open(versionfile_source, "w")
-        f.write(LONG_VERSION_PY % {"DOLLAR": "$",
-                                   "TAG_PREFIX": tag_prefix,
-                                   "PARENTDIR_PREFIX": parentdir_prefix,
-                                   "VERSIONFILE_SOURCE": versionfile_source,
-                                   })
-        f.close()
+
+def do_setup():
+    """Main VCS-independent setup function for installing Versioneer."""
+    root = get_root()
+    try:
+        cfg = get_config_from_root(root)
+    except (EnvironmentError, configparser.NoSectionError,
+            configparser.NoOptionError) as e:
+        if isinstance(e, (EnvironmentError, configparser.NoSectionError)):
+            print("Adding sample versioneer config to setup.cfg",
+                  file=sys.stderr)
+            with open(os.path.join(root, "setup.cfg"), "a") as f:
+                f.write(SAMPLE_CONFIG)
+        print(CONFIG_ERROR, file=sys.stderr)
+        return 1
+
+    print(" creating %s" % cfg.versionfile_source)
+    with open(cfg.versionfile_source, "w") as f:
+        LONG = LONG_VERSION_PY[cfg.VCS]
+        f.write(LONG % {"DOLLAR": "$",
+                        "STYLE": cfg.style,
+                        "TAG_PREFIX": cfg.tag_prefix,
+                        "PARENTDIR_PREFIX": cfg.parentdir_prefix,
+                        "VERSIONFILE_SOURCE": cfg.versionfile_source,
+                        })
+
+    ipy = os.path.join(os.path.dirname(cfg.versionfile_source),
+                       "__init__.py")
+    if os.path.exists(ipy):
         try:
-            old = open(ipy, "r").read()
+            with open(ipy, "r") as f:
+                old = f.read()
         except EnvironmentError:
             old = ""
         if INIT_PY_SNIPPET not in old:
             print(" appending to %s" % ipy)
-            f = open(ipy, "a")
-            f.write(INIT_PY_SNIPPET)
-            f.close()
+            with open(ipy, "a") as f:
+                f.write(INIT_PY_SNIPPET)
         else:
             print(" %s unmodified" % ipy)
-        do_vcs_install(versionfile_source, ipy)
+    else:
+        print(" %s doesn't exist, ok" % ipy)
+        ipy = None
+
+    # Make sure both the top-level "versioneer.py" and versionfile_source
+    # (PKG/_version.py, used by runtime code) are in MANIFEST.in, so
+    # they'll be copied into source distributions. Pip won't be able to
+    # install the package without this.
+    manifest_in = os.path.join(root, "MANIFEST.in")
+    simple_includes = set()
+    try:
+        with open(manifest_in, "r") as f:
+            for line in f:
+                if line.startswith("include "):
+                    for include in line.split()[1:]:
+                        simple_includes.add(include)
+    except EnvironmentError:
+        pass
+    # That doesn't cover everything MANIFEST.in can do
+    # (http://docs.python.org/2/distutils/sourcedist.html#commands), so
+    # it might give some false negatives. Appending redundant 'include'
+    # lines is safe, though.
+    if "versioneer.py" not in simple_includes:
+        print(" appending 'versioneer.py' to MANIFEST.in")
+        with open(manifest_in, "a") as f:
+            f.write("include versioneer.py\n")
+    else:
+        print(" 'versioneer.py' already in MANIFEST.in")
+    if cfg.versionfile_source not in simple_includes:
+        print(" appending versionfile_source ('%s') to MANIFEST.in" %
+              cfg.versionfile_source)
+        with open(manifest_in, "a") as f:
+            f.write("include %s\n" % cfg.versionfile_source)
+    else:
+        print(" versionfile_source already in MANIFEST.in")
 
-def get_cmdclass():
-    return {'version': cmd_version,
-            'update_files': cmd_update_files,
-            'build': cmd_build,
-            'sdist': cmd_sdist,
-            }
+    # Make VCS-specific changes. For git, this means creating/changing
+    # .gitattributes to mark _version.py for export-time keyword
+    # substitution.
+    do_vcs_install(manifest_in, cfg.versionfile_source, ipy)
+    return 0
+
+
+def scan_setup_py():
+    """Validate the contents of setup.py against Versioneer's expectations."""
+    found = set()
+    setters = False
+    errors = 0
+    with open("setup.py", "r") as f:
+        for line in f.readlines():
+            if "import versioneer" in line:
+                found.add("import")
+            if "versioneer.get_cmdclass()" in line:
+                found.add("cmdclass")
+            if "versioneer.get_version()" in line:
+                found.add("get_version")
+            if "versioneer.VCS" in line:
+                setters = True
+            if "versioneer.versionfile_source" in line:
+                setters = True
+    if len(found) != 3:
+        print("")
+        print("Your setup.py appears to be missing some important items")
+        print("(but I might be wrong). Please make sure it has something")
+        print("roughly like the following:")
+        print("")
+        print(" import versioneer")
+        print(" setup( version=versioneer.get_version(),")
+        print("        cmdclass=versioneer.get_cmdclass(),  ...)")
+        print("")
+        errors += 1
+    if setters:
+        print("You should remove lines like 'versioneer.VCS = ' and")
+        print("'versioneer.versionfile_source = ' . This configuration")
+        print("now lives in setup.cfg, and should be removed from setup.py")
+        print("")
+        errors += 1
+    return errors
+
+if __name__ == "__main__":
+    cmd = sys.argv[1]
+    if cmd == "setup":
+        errors = do_setup()
+        errors += scan_setup_py()
+        if errors:
+            sys.exit(1)