these 2 derivations will be built:
  /nix/store/czk2jcdkh8n15skfh93kmjj4a5vs2wgb-multica-0.9.0.drv
  /nix/store/8azxb5v7askfsj9qsybwc0ap9nbi5gpy-check-multica.drv
warning: SQLite database '/nix/var/nix/db/db.sqlite' is busy