these 2 derivations will be built:
  /nix/store/fim05jwdm0x5fxxqkli975grb4bz3mn7-iets-0.1.0.drv
  /nix/store/zcl09d922kvxc1a1fpc0v6yash44v1f0-iets-langtests.drv
warning: SQLite database '/nix/var/nix/db/db.sqlite' is busy