Don't use -warning=no-timestamp unless we have GNU tar
Don't use -warning=no-timestamp unless we have GNU tar

http://hydra.nixos.org/build/2998485

aucampia/nix,dtzWill/nix,offlinehacker/nix,rycee/nix,vcunat/nix,rowhit/nix,rycee/nix,bennofs/nix,gridaphobe/nix,layus/nix,ehmry/nix,tchajed/nix,offlinehacker/nix,NixOS/nix,layus/nix,jcumming/nix,garbas/nix,ysangkok/nix,gridaphobe/nix,vizanto/nix,dtzWill/nix,dezgeg/nix,vcunat/nix,puffnfresh/nix,gebner/nix,pikajude/nix,jcumming/nix,edolstra/nix,zimbatm/nix,offlinehacker/nix,layus/nix,bjornfor/nix,tchajed/nix,gridaphobe/nix,zimbatm/nix,zimbatm/nix,edolstra/nix,NixOS/nix,wmertens/nix,vizanto/nix,NixOS/nix,bjornfor/nix,bjornfor/nix,shlevy/nix,joelmo/nix,nbp/nix,puffnfresh/nix,peti/nix,wmertens/nix,acowley/nix,shlevy/nix,tchajed/nix,edolstra/nix,offlinehacker/nix,aucampia/nix,peti/nix,bennofs/nix,ehmry/nix,zimbatm/nix,vizanto/nix,edolstra/nix,garbas/nix,vcunat/nix,NixOS/nix,nbp/nix,puffnfresh/nix,ehmry/nix,rycee/nix,gridaphobe/nix,gebner/nix,dezgeg/nix,ysangkok/nix,bjornfor/nix,acowley/nix,rowhit/nix,dezgeg/nix,ttuegel/nix,garbas/nix,layus/nix,garbas/nix,dezgeg/nix,dezgeg/nix,aucampia/nix,joelmo/nix,jcumming/nix,ehmry/nix,ehmry/nix,dtzWill/nix,dtzWill/nix,pikajude/nix,nbp/nix,wmertens/nix,gebner/nix,shlevy/nix,joelmo/nix,ehmry/nix,ttuegel/nix,tchajed/nix,garbas/nix,rowhit/nix,acowley/nix,edolstra/nix,rycee/nix,jcumming/nix,rycee/nix,wmertens/nix,peti/nix,vizanto/nix,ttuegel/nix,dtzWill/nix,joelmo/nix,NixOS/nix,aucampia/nix,pikajude/nix,peti/nix,vcunat/nix,ttuegel/nix,puffnfresh/nix,acowley/nix,rowhit/nix,ysangkok/nix,bennofs/nix,gebner/nix,nbp/nix,peti/nix,layus/nix,shlevy/nix,bennofs/nix,shlevy/nix