anchor.diff:            default = true;
             description = "
               Whether to start the HAL daemon.
  +          ";
  +        };
  +
  +        extraFdi = mkOption {
  +          default = [];
  +          example = [ "/nix/store/.../fdi" ];
  +          description = "
  +            Extend HAL daemon configuration with additionnal paths.
             ";
           };
         };
  
positive.code:     gid = (import ../system/ids.nix).gids.haldaemon;
    };
  
  
    job = {
      name = "hal";
  
negative.code:           rm -f /var/cache/hald/fdi-cache
  
        end script
  
        # HACK ? These environment variables manipulated inside
        # 'src'/hald/mmap_cache.c are used for testing the daemon
        env HAL_FDI_SOURCE_PREPROBE=${fdi}/preprobe
        env HAL_FDI_SOURCE_INFORMATION=${fdi}/information
        env HAL_FDI_SOURCE_POLICY=${fdi}/policy
  
        respawn ${hal}/sbin/hald --daemon=no
      '';
  