this derivation will be built:
  /nix/store/wlfk5ssqm0jjb5y95xjfz1j4w7bd6xk6-inputDerivation-gh-pages.drv
building '/nix/store/wlfk5ssqm0jjb5y95xjfz1j4w7bd6xk6-inputDerivation-gh-pages.drv'...
warning: SQLite database '/nix/var/nix/db/db.sqlite' is busy