How to use the pip._internal.exceptions.InstallationError function in pip

'Could not find an activated virtualenv (required).'
                )
                sys.exit(VIRTUALENV_NOT_FOUND)

        try:
            status = self.run(options, args)
            # FIXME: all commands should return an exit status
            # and when it is done, isinstance is not needed anymore
            if isinstance(status, int):
                return status
        except PreviousBuildDirError as exc:
            logger.critical(str(exc))
            logger.debug('Exception information:', exc_info=True)

            return PREVIOUS_BUILD_DIR_ERROR
        except (InstallationError, UninstallationError, BadCommand) as exc:
            logger.critical(str(exc))
            logger.debug('Exception information:', exc_info=True)

            return ERROR
        except CommandError as exc:
            logger.critical('%s', exc)
            logger.debug('Exception information:', exc_info=True)

            return ERROR
        except BrokenStdoutLoggingError:
            # Bypass our logger and write any remaining messages to stderr
            # because stdout no longer works.
            print('ERROR: Pipe to stdout was broken', file=sys.stderr)
            if level_number <= logging.DEBUG:
                traceback.print_exc(file=sys.stderr)

if extras:
            return (
                package_name,
                url_no_extras,
                Requirement("placeholder" + extras.lower()).extras,
            )
        else:
            return package_name, url_no_extras, None

    for version_control in vcs:
        if url.lower().startswith('%s:' % version_control):
            url = '%s+%s' % (version_control, url)
            break

    if '+' not in url:
        raise InstallationError(
            '{} is not a valid editable requirement. '
            'It should either be a path to a local project or a VCS URL '
            '(beginning with svn+, git+, hg+, or bzr+).'.format(editable_req)
        )

    vc_type = url.split('+', 1)[0].lower()

    if not vcs.get_backend(vc_type):
        error_message = 'For --editable=%s only ' % editable_req + \
            ', '.join([backend.name + '+URL' for backend in vcs.backends]) + \
            ' is currently supported'
        raise InstallationError(error_message)

    package_name = Link(url).egg_fragment
    if not package_name:
        raise InstallationError(

'# Editable {} install with no remote ({})'.format(
                type(vcs_backend).__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,
            vcs_backend.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)

# 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 req.link.scheme in vcs.all_schemes:
                    req.archive(self.download_dir)
        return abstract_dist

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 from_req(cls, req, comes_from=None, isolated=False, wheel_cache=None):
        try:
            req = Requirement(req)
        except InvalidRequirement:
            raise InstallationError("Invalid requirement: '%s'" % req)
        if req.url:
            raise InstallationError(
                "Direct url requirement (like %s) are not allowed for "
                "dependencies" % req
            )
        return cls(req, comes_from, isolated=isolated, wheel_cache=wheel_cache)

def prepare_editable_requirement(self, req, require_hashes, use_user_site,
                                     finder):
        """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_editable_requirement(self, req, require_hashes, use_user_site,
                                     finder):
        """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

This is only called by self.run_egg_info to fix the temporary build
        directory.
        """
        if self.source_dir is not None:
            return
        assert self.req is not None
        assert self._temp_build_dir.path
        assert (self._ideal_build_dir is not None and
                self._ideal_build_dir.path)  # type: ignore
        old_location = self._temp_build_dir.path
        self._temp_build_dir.path = None

        new_location = self.build_location(self._ideal_build_dir)
        if os.path.exists(new_location):
            raise InstallationError(
                'A package already exists in %s; please remove it to continue'
                % display_path(new_location))
        logger.debug(
            'Moving package %s from %s to new location %s',
            self, display_path(old_location), display_path(new_location),
        )
        shutil.move(old_location, new_location)
        self._temp_build_dir.path = new_location
        self._ideal_build_dir = None
        self.source_dir = os.path.normpath(os.path.abspath(new_location))
        self._egg_info_path = None

        # Correct the metadata directory, if it exists
        if self.metadata_directory:
            old_meta = self.metadata_directory
            rel = os.path.relpath(old_meta, start=old_location)

def _raise_conflicts(conflicting_with, conflicting_reqs):
            format_string = (
                "Some build dependencies for {requirement} "
                "conflict with {conflicting_with}: {description}."
            )
            error_message = format_string.format(
                requirement=self.req,
                conflicting_with=conflicting_with,
                description=', '.join(
                    '%s is incompatible with %s' % (installed, wanted)
                    for installed, wanted in sorted(conflicting)
                )
            )
            raise InstallationError(error_message)