these 2 derivations will be built:
  /nix/store/4hg31mk9kalzm4d40f5r5ff0357fn1iq-ats2-0.4.2.drv
  /nix/store/inlrs8pprjj7sjanaimlim7rn8m8fg9f-ats-acc-unstable-2018-10-21.drv
these 2 paths will be fetched (4.4 MiB download, 4.4 MiB unpacked):
  /nix/store/5spajpssd35cf1h34i45mpvmn2ygjfpm-ATS2-Postiats-contrib-0.4.2.tgz
  /nix/store/z21xvafdijmya6ykhx9vs5j6mbcggnmm-ATS2-Postiats-gmp-0.4.2.tgz