these 4 derivations will be built:
  /nix/store/q1ai5nl86z77p7f51ipglip2cbnjfy6d-Cargo.toml.drv
  /nix/store/b3fdgp0475m6cw74xq1anqy0rkygc804-source.drv
  /nix/store/k8ihbr3sfqjlsfblr68bjccxjdzmqww7-harmonia-deps-3.2.0.drv
  /nix/store/yj0snplyy6dp1lda5dvasyx1qnkfy478-harmonia-3.2.0.drv