docs: def realpath(self, spec, key):
          """
          Resolve and update the path key in the spec with its realpath,
          based on the working directory.
          """
  
          if key not in spec:
              # do nothing for now
              return
  
          if not spec[key]:
              logger.warning(
                  "cannot resolve realpath of '%s' as it is not defined", key)
              return
  
          check = realpath(join(spec.get(WORKING_DIR, ''), spec[key]))
          if check != spec[key]:
              spec[key] = check
              logger.warning(
                  "realpath of '%s' resolved to '%s', spec is updated",
                  key, check
              )
          return check