Fix building on Darwin
Fix building on Darwin

Fixes #433.

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