these 4 derivations will be built:
  /nix/store/x2a6m8afnjb02rk9gmf83q7qyacrr4c5-Cargo.toml.drv
  /nix/store/089rdz6r89l92rixdxw4lka5q1pra00p-source.drv
  /nix/store/q046z0sckx8lnryzb41hvb3l23vm0vsj-harmonia-deps-3.2.0.drv
  /nix/store/7kx9464fx1hjhkmghhy9nmx0yi438b68-harmonia-3.2.0.drv