Create symbolic links to the output files produced by the other tasks.

        .. warning::

            This method should be called only when the calculation is READY because
            it uses a heuristic approach to find the file to link.

def make_links(self):
        """
        Create symbolic links to the output files produced by the other tasks.

        .. warning::

            This method should be called only when the calculation is READY because
            it uses a heuristic approach to find the file to link.
        """
        for dep in self.deps:
            filepaths, exts = dep.get_filepaths_and_exts()

            for path, ext in zip(filepaths, exts):
                logger.info("Need path %s with ext %s" % (path, ext))
                dest = self.ipath_from_ext(ext)

                if not os.path.exists(path):
                    # Try netcdf file.
                    # TODO: this case should be treated in a cleaner way.
                    path += ".nc"
                    if os.path.exists(path): dest += ".nc"

                if not os.path.exists(path):
                    raise self.Error("%s: %s is needed by this task but it does not exist" % (self, path))

                if path.endswith(".nc") and not dest.endswith(".nc"): # NC --> NC file
                    dest += ".nc"

                # Link path to dest if dest link does not exist.
                # else check that it points to the expected file.
                logger.debug("Linking path %s --> %s" % (path, dest))
                if not os.path.exists(dest):
                    os.symlink(path, dest)
                else:
                    # check links but only if we haven't performed the restart.
                    # in this case, indeed we may have replaced the file pointer with the
                    # previous output file of the present task.
                    if os.path.realpath(dest) != path and self.num_restarts == 0:
                        raise self.Error("\nDestination:\n %s\ndoes not point to path:\n %s" % (dest, path))