def unpack_source_dists(self, arguments, use_wheels=False):
        """
        Find and unpack local source distributions and discover their metadata.

        :param arguments: The command line arguments to ``pip install ...`` (a
                          list of strings).
        :param use_wheels: Whether pip and pip-accel are allowed to use wheels_
                           (:data:`False` by default for backwards compatibility
                           with callers that use pip-accel as a Python API).
        :returns: A list of :class:`pip_accel.req.Requirement` objects.
        :raises: Any exceptions raised by pip, for example
                 :exc:`pip.exceptions.DistributionNotFound` when not all
                 requirements can be satisfied.

        This function checks whether there are local source distributions
        available for all requirements, unpacks the source distribution
        archives and finds the names and versions of the requirements. By using
        the ``pip install --download`` command we avoid reimplementing the
        following pip features:

        - Parsing of ``requirements.txt`` (including recursive parsing).
        - Resolution of possibly conflicting pinned requirements.
        - Unpacking source distributions in multiple formats.
        - Finding the name & version of a given source distribution.
        """
        unpack_timer = Timer()
        logger.info("Unpacking distribution(s) ..")
        with PatchedAttribute(pip_install_module, 'PackageFinder', CustomPackageFinder):
            requirements = self.get_pip_requirement_set(arguments, use_remote_index=False, use_wheels=use_wheels)
            logger.info("Finished unpacking %s in %s.", pluralize(len(requirements), "distribution"), unpack_timer)
            return requirements
Find and unpack local source distributions and discover their metadata.

        :param arguments: The command line arguments to ``pip install ...`` (a
                          list of strings).
        :param use_wheels: Whether pip and pip-accel are allowed to use wheels_
                           (:data:`False` by default for backwards compatibility
                           with callers that use pip-accel as a Python API).
        :returns: A list of :class:`pip_accel.req.Requirement` objects.
        :raises: Any exceptions raised by pip, for example
                 :exc:`pip.exceptions.DistributionNotFound` when not all
                 requirements can be satisfied.

        This function checks whether there are local source distributions
        available for all requirements, unpacks the source distribution
        archives and finds the names and versions of the requirements. By using
        the ``pip install --download`` command we avoid reimplementing the
        following pip features:

        - Parsing of ``requirements.txt`` (including recursive parsing).
        - Resolution of possibly conflicting pinned requirements.
        - Unpacking source distributions in multiple formats.
        - Finding the name & version of a given source distribution.