these 4 derivations will be built:
  /nix/store/gmggjj0ddn7mjx4l4y2pkrvg30ak9d0z-cargo-nix-plugin-mirror-test-env-var.drv
  /nix/store/vdr5f6nny9lkrzjfqhzljj6l58nj7vj4-cargo-nix-plugin-mirror-test-cargo-config.drv
  /nix/store/y9p9kscy40885yk1a0k725bfj3f38pc9-cargo-nix-plugin-mirror-test-https-custom-ca.drv
  /nix/store/ag1wf824gij2rj7irhn5cbf7ckfk0312-cargo-nix-plugin-mirror-tests.drv
building '/nix/store/vdr5f6nny9lkrzjfqhzljj6l58nj7vj4-cargo-nix-plugin-mirror-test-cargo-config.drv' on 'ssh-ng://nix@jamie'
building '/nix/store/gmggjj0ddn7mjx4l4y2pkrvg30ak9d0z-cargo-nix-plugin-mirror-test-env-var.drv' on 'ssh-ng://nix@jamie'
building '/nix/store/y9p9kscy40885yk1a0k725bfj3f38pc9-cargo-nix-plugin-mirror-test-https-custom-ca.drv' on 'ssh-ng://nix@jamie'