these 2 derivations will be built:
  /nix/store/chh1xwkd47wjfn3yhhivkicvsp5rsc2c-iets-0.1.0.drv
  /nix/store/v5b4iwxzzfxyy821wg7jjxn2989gjdvz-iets-langtests.drv
warning: SQLite database '/nix/var/nix/db/db.sqlite' is busy