these 2 derivations will be built:
  /nix/store/rbmv2y08nrsdzsmb7rqw6vnlw8km4i2x-unreal-agent-0.2.0.drv
  /nix/store/if4fc6q0lfxabb4iyvv5f08aybf7h2hq-check-unreal-agent.drv