# Buggy code
def distutils_scheme(
    dist_name, user=False, home=None, root=None, isolated=False, prefix=None
):
    """
    Return a distutils install scheme
    """
    from distutils.dist import Distribution

    scheme = {}

    if isolated:
        extra_dist_args = {"script_args": ["--no-user-cfg"]}
    else:
        extra_dist_args = {}
    dist_args = {"name": dist_name}
    dist_args.update(extra_dist_args)

    d = Distribution(dist_args)
    d.parse_config_files()
    i = d.get_command_obj("install", create=True)
    # NOTE: setting user or home has the side-effect of creating the home dir
    # or user base for installations during finalize_options()
    # ideally, we'd prefer a scheme class that has no side-effects.
    assert not (user and prefix), "user={} prefix={}".format(user, prefix)
    i.user = user or i.user
    if user or home:
        i.prefix = ""
    i.prefix = prefix or i.prefix
    i.home = home or i.home
    i.root = root or i.root
    i.finalize_options()
    for key in SCHEME_KEYS:
        scheme[key] = getattr(i, "install_" + key)

    # install_lib specified in setup.cfg should install *everything*
    # into there (i.e. it takes precedence over both purelib and
    # platlib).  Note, i.install_lib is *always* set after
    # finalize_options(); we only want to override here if the user
    # has explicitly requested it hence going back to the config
    if "install_lib" in d.get_option_dict("install"):
        scheme.update(dict(purelib=i.install_lib, platlib=i.install_lib))

    if running_under_virtualenv():
        scheme["headers"] = os.path.join(
            sys.prefix,
            "include",
            "site",
            "python" + sys.version[:3],
            dist_name,
        )

        if root is not None:
            path_no_drive = os.path.splitdrive(os.path.abspath(scheme["headers"]))[1]
            scheme["headers"] = os.path.join(
                root,
                path_no_drive[1:],
            )

    return scheme


# Traceback (DistutilsOptionError)
$ python2.7 -m pip install -t foo requests
Collecting requests
Using cached requests-2.11.1-py2.py3-none-any.whl
Installing collected packages: requests
Exception:
Traceback (most recent call last):
File "/usr/local/lib/python2.7/site-packages/pip/basecommand.py", line 215, in main
status = self.run(options, args)
File "/usr/local/lib/python2.7/site-packages/pip/commands/install.py", line 342, in run
prefix=options.prefix_path,
File "/usr/local/lib/python2.7/site-packages/pip/req/req_set.py", line 784, in install
**kwargs
File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 851, in install
self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 1064, in move_wheel_files
isolated=self.isolated,
File "/usr/local/lib/python2.7/site-packages/pip/wheel.py", line 247, in move_wheel_files
prefix=prefix,
File "/usr/local/lib/python2.7/site-packages/pip/locations.py", line 153, in distutils_scheme
i.finalize_options()
File "/usr/local/Cellar/python/2.7.12_2/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/command/install.py", line 264, in finalize_options
"must supply either home or prefix/exec-prefix -- not both"
DistutilsOptionError: must supply either home or prefix/exec-prefix -- not both

# Fixed code
def distutils_scheme(
    dist_name, user=False, home=None, root=None, isolated=False, prefix=None
):
    """
    Return a distutils install scheme
    """
    from distutils.dist import Distribution

    scheme = {}

    if isolated:
        extra_dist_args = {"script_args": ["--no-user-cfg"]}
    else:
        extra_dist_args = {}
    dist_args = {"name": dist_name}
    dist_args.update(extra_dist_args)

    d = Distribution(dist_args)
    d.parse_config_files()
    i = d.get_command_obj("install", create=True)
    # NOTE: setting user or home has the side-effect of creating the home dir
    # or user base for installations during finalize_options()
    # ideally, we'd prefer a scheme class that has no side-effects.
    assert not (user and prefix), "user={} prefix={}".format(user, prefix)
    assert not (home and prefix), "home={} prefix={}".format(home, prefix)
    i.user = user or i.user
    if user or home:
        i.prefix = ""
    i.prefix = prefix or i.prefix
    i.home = home or i.home
    i.root = root or i.root
    i.finalize_options()
    for key in SCHEME_KEYS:
        scheme[key] = getattr(i, "install_" + key)

    # install_lib specified in setup.cfg should install *everything*
    # into there (i.e. it takes precedence over both purelib and
    # platlib).  Note, i.install_lib is *always* set after
    # finalize_options(); we only want to override here if the user
    # has explicitly requested it hence going back to the config
    if "install_lib" in d.get_option_dict("install"):
        scheme.update(dict(purelib=i.install_lib, platlib=i.install_lib))

    if running_under_virtualenv():
        scheme["headers"] = os.path.join(
            sys.prefix,
            "include",
            "site",
            "python" + sys.version[:3],
            dist_name,
        )

        if root is not None:
            path_no_drive = os.path.splitdrive(os.path.abspath(scheme["headers"]))[1]
            scheme["headers"] = os.path.join(
                root,
                path_no_drive[1:],
            )

    return scheme