add zsh h()

venv/lib/python2.7/site-packages/pip/_internal/operations/check.py

@@ -0,0 +1,155 @@
+"""Validation of dependencies of packages
+"""
+
+import logging
+from collections import namedtuple
+
+from pip._vendor.packaging.utils import canonicalize_name
+from pip._vendor.pkg_resources import RequirementParseError
+
+from pip._internal.operations.prepare import make_abstract_dist
+from pip._internal.utils.misc import get_installed_distributions
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+logger = logging.getLogger(__name__)
+
+if MYPY_CHECK_RUNNING:
+    from pip._internal.req.req_install import InstallRequirement
+    from typing import (
+        Any, Callable, Dict, Optional, Set, Tuple, List
+    )
+
+    # Shorthands
+    PackageSet = Dict[str, 'PackageDetails']
+    Missing = Tuple[str, Any]
+    Conflicting = Tuple[str, str, Any]
+
+    MissingDict = Dict[str, List[Missing]]
+    ConflictingDict = Dict[str, List[Conflicting]]
+    CheckResult = Tuple[MissingDict, ConflictingDict]
+
+PackageDetails = namedtuple('PackageDetails', ['version', 'requires'])
+
+
+def create_package_set_from_installed(**kwargs):
+    # type: (**Any) -> Tuple[PackageSet, bool]
+    """Converts a list of distributions into a PackageSet.
+    """
+    # Default to using all packages installed on the system
+    if kwargs == {}:
+        kwargs = {"local_only": False, "skip": ()}
+
+    package_set = {}
+    problems = False
+    for dist in get_installed_distributions(**kwargs):
+        name = canonicalize_name(dist.project_name)
+        try:
+            package_set[name] = PackageDetails(dist.version, dist.requires())
+        except RequirementParseError as e:
+            # Don't crash on broken metadata
+            logging.warning("Error parsing requirements for %s: %s", name, e)
+            problems = True
+    return package_set, problems
+
+
+def check_package_set(package_set, should_ignore=None):
+    # type: (PackageSet, Optional[Callable[[str], bool]]) -> CheckResult
+    """Check if a package set is consistent
+
+    If should_ignore is passed, it should be a callable that takes a
+    package name and returns a boolean.
+    """
+    if should_ignore is None:
+        def should_ignore(name):
+            return False
+
+    missing = dict()
+    conflicting = dict()
+
+    for package_name in package_set:
+        # Info about dependencies of package_name
+        missing_deps = set()  # type: Set[Missing]
+        conflicting_deps = set()  # type: Set[Conflicting]
+
+        if should_ignore(package_name):
+            continue
+
+        for req in package_set[package_name].requires:
+            name = canonicalize_name(req.project_name)  # type: str
+
+            # Check if it's missing
+            if name not in package_set:
+                missed = True
+                if req.marker is not None:
+                    missed = req.marker.evaluate()
+                if missed:
+                    missing_deps.add((name, req))
+                continue
+
+            # Check if there's a conflict
+            version = package_set[name].version  # type: str
+            if not req.specifier.contains(version, prereleases=True):
+                conflicting_deps.add((name, version, req))
+
+        if missing_deps:
+            missing[package_name] = sorted(missing_deps, key=str)
+        if conflicting_deps:
+            conflicting[package_name] = sorted(conflicting_deps, key=str)
+
+    return missing, conflicting
+
+
+def check_install_conflicts(to_install):
+    # type: (List[InstallRequirement]) -> Tuple[PackageSet, CheckResult]
+    """For checking if the dependency graph would be consistent after \
+    installing given requirements
+    """
+    # Start from the current state
+    package_set, _ = create_package_set_from_installed()
+    # Install packages
+    would_be_installed = _simulate_installation_of(to_install, package_set)
+
+    # Only warn about directly-dependent packages; create a whitelist of them
+    whitelist = _create_whitelist(would_be_installed, package_set)
+
+    return (
+        package_set,
+        check_package_set(
+            package_set, should_ignore=lambda name: name not in whitelist
+        )
+    )
+
+
+def _simulate_installation_of(to_install, package_set):
+    # type: (List[InstallRequirement], PackageSet) -> Set[str]
+    """Computes the version of packages after installing to_install.
+    """
+
+    # Keep track of packages that were installed
+    installed = set()
+
+    # Modify it as installing requirement_set would (assuming no errors)
+    for inst_req in to_install:
+        dist = make_abstract_dist(inst_req).dist()
+        name = canonicalize_name(dist.key)
+        package_set[name] = PackageDetails(dist.version, dist.requires())
+
+        installed.add(name)
+
+    return installed
+
+
+def _create_whitelist(would_be_installed, package_set):
+    # type: (Set[str], PackageSet) -> Set[str]
+    packages_affected = set(would_be_installed)
+
+    for package_name in package_set:
+        if package_name in packages_affected:
+            continue
+
+        for req in package_set[package_name].requires:
+            if canonicalize_name(req.name) in packages_affected:
+                packages_affected.add(package_name)
+                break
+
+    return packages_affected

venv/lib/python2.7/site-packages/pip/_internal/operations/freeze.py

@@ -0,0 +1,247 @@
+from __future__ import absolute_import
+
+import collections
+import logging
+import os
+import re
+
+from pip._vendor import six
+from pip._vendor.packaging.utils import canonicalize_name
+from pip._vendor.pkg_resources import RequirementParseError
+
+from pip._internal.exceptions import BadCommand, InstallationError
+from pip._internal.req.constructors import (
+    install_req_from_editable, install_req_from_line,
+)
+from pip._internal.req.req_file import COMMENT_RE
+from pip._internal.utils.misc import (
+    dist_is_editable, get_installed_distributions,
+)
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import (
+        Iterator, Optional, List, Container, Set, Dict, Tuple, Iterable, Union
+    )
+    from pip._internal.cache import WheelCache
+    from pip._vendor.pkg_resources import (
+        Distribution, Requirement
+    )
+
+    RequirementInfo = Tuple[Optional[Union[str, Requirement]], bool, List[str]]
+
+
+logger = logging.getLogger(__name__)
+
+
+def freeze(
+    requirement=None,  # type: Optional[List[str]]
+    find_links=None,  # type: Optional[List[str]]
+    local_only=None,  # type: Optional[bool]
+    user_only=None,  # type: Optional[bool]
+    skip_regex=None,  # type: Optional[str]
+    isolated=False,  # type: bool
+    wheel_cache=None,  # type: Optional[WheelCache]
+    exclude_editable=False,  # type: bool
+    skip=()  # type: Container[str]
+):
+    # type: (...) -> Iterator[str]
+    find_links = find_links or []
+    skip_match = None
+
+    if skip_regex:
+        skip_match = re.compile(skip_regex).search
+
+    for link in find_links:
+        yield '-f %s' % link
+    installations = {}  # type: Dict[str, FrozenRequirement]
+    for dist in get_installed_distributions(local_only=local_only,
+                                            skip=(),
+                                            user_only=user_only):
+        try:
+            req = FrozenRequirement.from_dist(dist)
+        except RequirementParseError:
+            logger.warning(
+                "Could not parse requirement: %s",
+                dist.project_name
+            )
+            continue
+        if exclude_editable and req.editable:
+            continue
+        installations[req.name] = req
+
+    if requirement:
+        # the options that don't get turned into an InstallRequirement
+        # should only be emitted once, even if the same option is in multiple
+        # requirements files, so we need to keep track of what has been emitted
+        # so that we don't emit it again if it's seen again
+        emitted_options = set()  # type: Set[str]
+        # keep track of which files a requirement is in so that we can
+        # give an accurate warning if a requirement appears multiple times.
+        req_files = collections.defaultdict(list)  # type: Dict[str, List[str]]
+        for req_file_path in requirement:
+            with open(req_file_path) as req_file:
+                for line in req_file:
+                    if (not line.strip() or
+                            line.strip().startswith('#') or
+                            (skip_match and skip_match(line)) or
+                            line.startswith((
+                                '-r', '--requirement',
+                                '-Z', '--always-unzip',
+                                '-f', '--find-links',
+                                '-i', '--index-url',
+                                '--pre',
+                                '--trusted-host',
+                                '--process-dependency-links',
+                                '--extra-index-url'))):
+                        line = line.rstrip()
+                        if line not in emitted_options:
+                            emitted_options.add(line)
+                            yield line
+                        continue
+
+                    if line.startswith('-e') or line.startswith('--editable'):
+                        if line.startswith('-e'):
+                            line = line[2:].strip()
+                        else:
+                            line = line[len('--editable'):].strip().lstrip('=')
+                        line_req = install_req_from_editable(
+                            line,
+                            isolated=isolated,
+                            wheel_cache=wheel_cache,
+                        )
+                    else:
+                        line_req = install_req_from_line(
+                            COMMENT_RE.sub('', line).strip(),
+                            isolated=isolated,
+                            wheel_cache=wheel_cache,
+                        )
+
+                    if not line_req.name:
+                        logger.info(
+                            "Skipping line in requirement file [%s] because "
+                            "it's not clear what it would install: %s",
+                            req_file_path, line.strip(),
+                        )
+                        logger.info(
+                            "  (add #egg=PackageName to the URL to avoid"
+                            " this warning)"
+                        )
+                    elif line_req.name not in installations:
+                        # either it's not installed, or it is installed
+                        # but has been processed already
+                        if not req_files[line_req.name]:
+                            logger.warning(
+                                "Requirement file [%s] contains %s, but "
+                                "package %r is not installed",
+                                req_file_path,
+                                COMMENT_RE.sub('', line).strip(), line_req.name
+                            )
+                        else:
+                            req_files[line_req.name].append(req_file_path)
+                    else:
+                        yield str(installations[line_req.name]).rstrip()
+                        del installations[line_req.name]
+                        req_files[line_req.name].append(req_file_path)
+
+        # Warn about requirements that were included multiple times (in a
+        # single requirements file or in different requirements files).
+        for name, files in six.iteritems(req_files):
+            if len(files) > 1:
+                logger.warning("Requirement %s included multiple times [%s]",
+                               name, ', '.join(sorted(set(files))))
+
+        yield(
+            '## The following requirements were added by '
+            'pip freeze:'
+        )
+    for installation in sorted(
+            installations.values(), key=lambda x: x.name.lower()):
+        if canonicalize_name(installation.name) not in skip:
+            yield str(installation).rstrip()
+
+
+def get_requirement_info(dist):
+    # type: (Distribution) -> RequirementInfo
+    """
+    Compute and return values (req, editable, comments) for use in
+    FrozenRequirement.from_dist().
+    """
+    if not dist_is_editable(dist):
+        return (None, False, [])
+
+    location = os.path.normcase(os.path.abspath(dist.location))
+
+    from pip._internal.vcs import vcs, RemoteNotFoundError
+    vc_type = vcs.get_backend_type(location)
+
+    if not vc_type:
+        req = dist.as_requirement()
+        logger.debug(
+            'No VCS found for editable requirement {!r} in: {!r}', req,
+            location,
+        )
+        comments = [
+            '# Editable install with no version control ({})'.format(req)
+        ]
+        return (location, True, comments)
+
+    try:
+        req = vc_type.get_src_requirement(location, dist.project_name)
+    except RemoteNotFoundError:
+        req = dist.as_requirement()
+        comments = [
+            '# Editable {} install with no remote ({})'.format(
+                vc_type.__name__, req,
+            )
+        ]
+        return (location, True, comments)
+
+    except BadCommand:
+        logger.warning(
+            'cannot determine version of editable source in %s '
+            '(%s command not found in path)',
+            location,
+            vc_type.name,
+        )
+        return (None, True, [])
+
+    except InstallationError as exc:
+        logger.warning(
+            "Error when trying to get requirement for VCS system %s, "
+            "falling back to uneditable format", exc
+        )
+    else:
+        if req is not None:
+            return (req, True, [])
+
+    logger.warning(
+        'Could not determine repository location of %s', location
+    )
+    comments = ['## !! Could not determine repository location']
+
+    return (None, False, comments)
+
+
+class FrozenRequirement(object):
+    def __init__(self, name, req, editable, comments=()):
+        # type: (str, Union[str, Requirement], bool, Iterable[str]) -> None
+        self.name = name
+        self.req = req
+        self.editable = editable
+        self.comments = comments
+
+    @classmethod
+    def from_dist(cls, dist):
+        # type: (Distribution) -> FrozenRequirement
+        req, editable, comments = get_requirement_info(dist)
+        if req is None:
+            req = dist.as_requirement()
+
+        return cls(dist.project_name, req, editable, comments=comments)
+
+    def __str__(self):
+        req = self.req
+        if self.editable:
+            req = '-e %s' % req
+        return '\n'.join(list(self.comments) + [str(req)]) + '\n'

venv/lib/python2.7/site-packages/pip/_internal/operations/prepare.py

@@ -0,0 +1,426 @@
+"""Prepares a distribution for installation
+"""
+
+import logging
+import os
+
+from pip._vendor import pkg_resources, requests
+
+from pip._internal.build_env import BuildEnvironment
+from pip._internal.download import (
+    is_dir_url, is_file_url, is_vcs_url, unpack_url, url_to_path,
+)
+from pip._internal.exceptions import (
+    DirectoryUrlHashUnsupported, HashUnpinned, InstallationError,
+    PreviousBuildDirError, VcsHashUnsupported,
+)
+from pip._internal.utils.compat import expanduser
+from pip._internal.utils.hashes import MissingHashes
+from pip._internal.utils.logging import indent_log
+from pip._internal.utils.misc import display_path, normalize_path
+from pip._internal.utils.typing import MYPY_CHECK_RUNNING
+
+if MYPY_CHECK_RUNNING:
+    from typing import Any, Optional
+    from pip._internal.req.req_install import InstallRequirement
+    from pip._internal.index import PackageFinder
+    from pip._internal.download import PipSession
+    from pip._internal.req.req_tracker import RequirementTracker
+
+logger = logging.getLogger(__name__)
+
+
+def make_abstract_dist(req):
+    # type: (InstallRequirement) -> DistAbstraction
+    """Factory to make an abstract dist object.
+
+    Preconditions: Either an editable req with a source_dir, or satisfied_by or
+    a wheel link, or a non-editable req with a source_dir.
+
+    :return: A concrete DistAbstraction.
+    """
+    if req.editable:
+        return IsSDist(req)
+    elif req.link and req.link.is_wheel:
+        return IsWheel(req)
+    else:
+        return IsSDist(req)
+
+
+class DistAbstraction(object):
+    """Abstracts out the wheel vs non-wheel Resolver.resolve() logic.
+
+    The requirements for anything installable are as follows:
+     - we must be able to determine the requirement name
+       (or we can't correctly handle the non-upgrade case).
+     - we must be able to generate a list of run-time dependencies
+       without installing any additional packages (or we would
+       have to either burn time by doing temporary isolated installs
+       or alternatively violate pips 'don't start installing unless
+       all requirements are available' rule - neither of which are
+       desirable).
+     - for packages with setup requirements, we must also be able
+       to determine their requirements without installing additional
+       packages (for the same reason as run-time dependencies)
+     - we must be able to create a Distribution object exposing the
+       above metadata.
+    """
+
+    def __init__(self, req):
+        # type: (InstallRequirement) -> None
+        self.req = req  # type: InstallRequirement
+
+    def dist(self):
+        # type: () -> Any
+        """Return a setuptools Dist object."""
+        raise NotImplementedError
+
+    def prep_for_dist(self, finder, build_isolation):
+        # type: (PackageFinder, bool) -> Any
+        """Ensure that we can get a Dist for this requirement."""
+        raise NotImplementedError
+
+
+class IsWheel(DistAbstraction):
+
+    def dist(self):
+        # type: () -> pkg_resources.Distribution
+        return list(pkg_resources.find_distributions(
+            self.req.source_dir))[0]
+
+    def prep_for_dist(self, finder, build_isolation):
+        # type: (PackageFinder, bool) -> Any
+        # FIXME:https://github.com/pypa/pip/issues/1112
+        pass
+
+
+class IsSDist(DistAbstraction):
+
+    def dist(self):
+        return self.req.get_dist()
+
+    def _raise_conflicts(self, conflicting_with, conflicting_reqs):
+        conflict_messages = [
+            '%s is incompatible with %s' % (installed, wanted)
+            for installed, wanted in sorted(conflicting_reqs)
+        ]
+        raise InstallationError(
+            "Some build dependencies for %s conflict with %s: %s." % (
+                self.req, conflicting_with, ', '.join(conflict_messages))
+        )
+
+    def install_backend_dependencies(self, finder):
+        # type: (PackageFinder) -> None
+        """
+        Install any extra build dependencies that the backend requests.
+
+        :param finder: a PackageFinder object.
+        """
+        req = self.req
+        with req.build_env:
+            # We need to have the env active when calling the hook.
+            req.spin_message = "Getting requirements to build wheel"
+            reqs = req.pep517_backend.get_requires_for_build_wheel()
+        conflicting, missing = req.build_env.check_requirements(reqs)
+        if conflicting:
+            self._raise_conflicts("the backend dependencies", conflicting)
+        req.build_env.install_requirements(
+            finder, missing, 'normal',
+            "Installing backend dependencies"
+        )
+
+    def prep_for_dist(self, finder, build_isolation):
+        # type: (PackageFinder, bool) -> None
+        # Prepare for building. We need to:
+        #   1. Load pyproject.toml (if it exists)
+        #   2. Set up the build environment
+
+        self.req.load_pyproject_toml()
+        should_isolate = self.req.use_pep517 and build_isolation
+
+        if should_isolate:
+            # Isolate in a BuildEnvironment and install the build-time
+            # requirements.
+            self.req.build_env = BuildEnvironment()
+            self.req.build_env.install_requirements(
+                finder, self.req.pyproject_requires, 'overlay',
+                "Installing build dependencies"
+            )
+            conflicting, missing = self.req.build_env.check_requirements(
+                self.req.requirements_to_check
+            )
+            if conflicting:
+                self._raise_conflicts("PEP 517/518 supported requirements",
+                                      conflicting)
+            if missing:
+                logger.warning(
+                    "Missing build requirements in pyproject.toml for %s.",
+                    self.req,
+                )
+                logger.warning(
+                    "The project does not specify a build backend, and "
+                    "pip cannot fall back to setuptools without %s.",
+                    " and ".join(map(repr, sorted(missing)))
+                )
+
+            # Install any extra build dependencies that the backend requests.
+            # This must be done in a second pass, as the pyproject.toml
+            # dependencies must be installed before we can call the backend.
+            self.install_backend_dependencies(finder=finder)
+
+        self.req.prepare_metadata()
+        self.req.assert_source_matches_version()
+
+
+class Installed(DistAbstraction):
+
+    def dist(self):
+        # type: () -> pkg_resources.Distribution
+        return self.req.satisfied_by
+
+    def prep_for_dist(self, finder, build_isolation):
+        # type: (PackageFinder, bool) -> Any
+        pass
+
+
+class RequirementPreparer(object):
+    """Prepares a Requirement
+    """
+
+    def __init__(
+        self,
+        build_dir,  # type: str
+        download_dir,  # type: Optional[str]
+        src_dir,  # type: str
+        wheel_download_dir,  # type: Optional[str]
+        progress_bar,  # type: str
+        build_isolation,  # type: bool
+        req_tracker  # type: RequirementTracker
+    ):
+        # type: (...) -> None
+        super(RequirementPreparer, self).__init__()
+
+        self.src_dir = src_dir
+        self.build_dir = build_dir
+        self.req_tracker = req_tracker
+
+        # Where still packed archives should be written to. If None, they are
+        # not saved, and are deleted immediately after unpacking.
+        self.download_dir = download_dir
+
+        # Where still-packed .whl files should be written to. If None, they are
+        # written to the download_dir parameter. Separate to download_dir to
+        # permit only keeping wheel archives for pip wheel.
+        if wheel_download_dir:
+            wheel_download_dir = normalize_path(wheel_download_dir)
+        self.wheel_download_dir = wheel_download_dir
+
+        # NOTE
+        # download_dir and wheel_download_dir overlap semantically and may
+        # be combined if we're willing to have non-wheel archives present in
+        # the wheelhouse output by 'pip wheel'.
+
+        self.progress_bar = progress_bar
+
+        # Is build isolation allowed?
+        self.build_isolation = build_isolation
+
+    @property
+    def _download_should_save(self):
+        # type: () -> bool
+        # TODO: Modify to reduce indentation needed
+        if self.download_dir:
+            self.download_dir = expanduser(self.download_dir)
+            if os.path.exists(self.download_dir):
+                return True
+            else:
+                logger.critical('Could not find download directory')
+                raise InstallationError(
+                    "Could not find or access download directory '%s'"
+                    % display_path(self.download_dir))
+        return False
+
+    def prepare_linked_requirement(
+        self,
+        req,  # type: InstallRequirement
+        session,  # type: PipSession
+        finder,  # type: PackageFinder
+        upgrade_allowed,  # type: bool
+        require_hashes  # type: bool
+    ):
+        # type: (...) -> DistAbstraction
+        """Prepare a requirement that would be obtained from req.link
+        """
+        # TODO: Breakup into smaller functions
+        if req.link and req.link.scheme == 'file':
+            path = url_to_path(req.link.url)
+            logger.info('Processing %s', display_path(path))
+        else:
+            logger.info('Collecting %s', req)
+
+        with indent_log():
+            # @@ if filesystem packages are not marked
+            # editable in a req, a non deterministic error
+            # occurs when the script attempts to unpack the
+            # build directory
+            req.ensure_has_source_dir(self.build_dir)
+            # If a checkout exists, it's unwise to keep going.  version
+            # inconsistencies are logged later, but do not fail the
+            # installation.
+            # FIXME: this won't upgrade when there's an existing
+            # package unpacked in `req.source_dir`
+            # package unpacked in `req.source_dir`
+            if os.path.exists(os.path.join(req.source_dir, 'setup.py')):
+                raise PreviousBuildDirError(
+                    "pip can't proceed with requirements '%s' due to a"
+                    " pre-existing build directory (%s). This is "
+                    "likely due to a previous installation that failed"
+                    ". pip is being responsible and not assuming it "
+                    "can delete this. Please delete it and try again."
+                    % (req, req.source_dir)
+                )
+            req.populate_link(finder, upgrade_allowed, require_hashes)
+
+            # We can't hit this spot and have populate_link return None.
+            # req.satisfied_by is None here (because we're
+            # guarded) and upgrade has no impact except when satisfied_by
+            # is not None.
+            # Then inside find_requirement existing_applicable -> False
+            # If no new versions are found, DistributionNotFound is raised,
+            # otherwise a result is guaranteed.
+            assert req.link
+            link = req.link
+
+            # Now that we have the real link, we can tell what kind of
+            # requirements we have and raise some more informative errors
+            # than otherwise. (For example, we can raise VcsHashUnsupported
+            # for a VCS URL rather than HashMissing.)
+            if require_hashes:
+                # We could check these first 2 conditions inside
+                # unpack_url and save repetition of conditions, but then
+                # we would report less-useful error messages for
+                # unhashable requirements, complaining that there's no
+                # hash provided.
+                if is_vcs_url(link):
+                    raise VcsHashUnsupported()
+                elif is_file_url(link) and is_dir_url(link):
+                    raise DirectoryUrlHashUnsupported()
+                if not req.original_link and not req.is_pinned:
+                    # Unpinned packages are asking for trouble when a new
+                    # version is uploaded. This isn't a security check, but
+                    # it saves users a surprising hash mismatch in the
+                    # future.
+                    #
+                    # file:/// URLs aren't pinnable, so don't complain
+                    # about them not being pinned.
+                    raise HashUnpinned()
+
+            hashes = req.hashes(trust_internet=not require_hashes)
+            if require_hashes and not hashes:
+                # Known-good hashes are missing for this requirement, so
+                # shim it with a facade object that will provoke hash
+                # computation and then raise a HashMissing exception
+                # showing the user what the hash should be.
+                hashes = MissingHashes()
+
+            try:
+                download_dir = self.download_dir
+                # We always delete unpacked sdists after pip ran.
+                autodelete_unpacked = True
+                if req.link.is_wheel and self.wheel_download_dir:
+                    # when doing 'pip wheel` we download wheels to a
+                    # dedicated dir.
+                    download_dir = self.wheel_download_dir
+                if req.link.is_wheel:
+                    if download_dir:
+                        # When downloading, we only unpack wheels to get
+                        # metadata.
+                        autodelete_unpacked = True
+                    else:
+                        # When installing a wheel, we use the unpacked
+                        # wheel.
+                        autodelete_unpacked = False
+                unpack_url(
+                    req.link, req.source_dir,
+                    download_dir, autodelete_unpacked,
+                    session=session, hashes=hashes,
+                    progress_bar=self.progress_bar
+                )
+            except requests.HTTPError as exc:
+                logger.critical(
+                    'Could not install requirement %s because of error %s',
+                    req,
+                    exc,
+                )
+                raise InstallationError(
+                    'Could not install requirement %s because of HTTP '
+                    'error %s for URL %s' %
+                    (req, exc, req.link)
+                )
+            abstract_dist = make_abstract_dist(req)
+            with self.req_tracker.track(req):
+                abstract_dist.prep_for_dist(finder, self.build_isolation)
+            if self._download_should_save:
+                # Make a .zip of the source_dir we already created.
+                if not req.link.is_artifact:
+                    req.archive(self.download_dir)
+        return abstract_dist
+
+    def prepare_editable_requirement(
+        self,
+        req,  # type: InstallRequirement
+        require_hashes,  # type: bool
+        use_user_site,  # type: bool
+        finder  # type: PackageFinder
+    ):
+        # type: (...) -> DistAbstraction
+        """Prepare an editable requirement
+        """
+        assert req.editable, "cannot prepare a non-editable req as editable"
+
+        logger.info('Obtaining %s', req)
+
+        with indent_log():
+            if require_hashes:
+                raise InstallationError(
+                    'The editable requirement %s cannot be installed when '
+                    'requiring hashes, because there is no single file to '
+                    'hash.' % req
+                )
+            req.ensure_has_source_dir(self.src_dir)
+            req.update_editable(not self._download_should_save)
+
+            abstract_dist = make_abstract_dist(req)
+            with self.req_tracker.track(req):
+                abstract_dist.prep_for_dist(finder, self.build_isolation)
+
+            if self._download_should_save:
+                req.archive(self.download_dir)
+            req.check_if_exists(use_user_site)
+
+        return abstract_dist
+
+    def prepare_installed_requirement(self, req, require_hashes, skip_reason):
+        # type: (InstallRequirement, bool, Optional[str]) -> DistAbstraction
+        """Prepare an already-installed requirement
+        """
+        assert req.satisfied_by, "req should have been satisfied but isn't"
+        assert skip_reason is not None, (
+            "did not get skip reason skipped but req.satisfied_by "
+            "is set to %r" % (req.satisfied_by,)
+        )
+        logger.info(
+            'Requirement %s: %s (%s)',
+            skip_reason, req, req.satisfied_by.version
+        )
+        with indent_log():
+            if require_hashes:
+                logger.debug(
+                    'Since it is already installed, we are trusting this '
+                    'package without checking its hash. To ensure a '
+                    'completely repeatable environment, install into an '
+                    'empty virtualenv.'
+                )
+            abstract_dist = Installed(req)
+
+        return abstract_dist