this derivation will be built:
  /nix/store/377hh34zsx3qgfj0azbvpjj5frbd87rw-mpv-convert-script-2016-03-18.drv
these 7 paths will be fetched (4.8 MiB download, 28.1 MiB unpacked):
  /nix/store/df5wzcvmwlnmcc0pw9z9h2sgq9ij5dvq-fmt-7.1.3
  /nix/store/6ghnsh9ha5jxbw6a2b611k6jjk1zm7wg-fmt-7.1.3-dev
  /nix/store/i7cdswgfvrdbqw96cmk28m7jccgbr9s5-libebml-1.4.4
  /nix/store/wjg5d1q9xyjd6isx7h56nx69jzkwk650-libmatroska-1.7.1
  /nix/store/n3mhhlk3l1qasw4nsbr29mj78bwnfmhr-mkvtoolnix-73.0.0
  /nix/store/v2v4lblycv6cmfdybyazp63ggvzhxrkn-nlohmann_json-3.11.2
  /nix/store/4m285fmh21lpvds7mlq6kd02w3y6dhg8-yad-12.1
warning: SQLite database '/nix/var/nix/db/db.sqlite' is busy