code: def _check_file_is_under_workingdir(filename, wdir):
          
          p = filename
          if not os.path.isabs(p):
              p = os.path.join(wdir, p)
          targetpath = os.path.realpath(p)
          wdir = os.path.realpath(wdir)
          common = os.path.commonprefix([wdir, targetpath])
          if len(common) < len(wdir):
              raise exceptions.PathError(
                      "The subprocess engine does not support input files with absolute paths")
          return p
docs: Raise error if input is being staged to a location not underneath the working dir