Propagate NIX_BUILD_CORES to nix-shell environments
Propagate NIX_BUILD_CORES to nix-shell environments

dtzWill/nix,peti/nix,dezgeg/nix,ehmry/nix,zimbatm/nix,shlevy/nix,shlevy/nix,pikajude/nix,peti/nix,NixOS/nix,zimbatm/nix,shlevy/nix,layus/nix,NixOS/nix,rycee/nix,layus/nix,ehmry/nix,dezgeg/nix,peti/nix,rycee/nix,rycee/nix,peti/nix,NixOS/nix,zimbatm/nix,shlevy/nix,NixOS/nix,layus/nix,ehmry/nix,vcunat/nix,vcunat/nix,pikajude/nix,dezgeg/nix,vcunat/nix,layus/nix,rycee/nix,rycee/nix,layus/nix,dtzWill/nix,ehmry/nix,ehmry/nix,dtzWill/nix,shlevy/nix,NixOS/nix,zimbatm/nix,dtzWill/nix,pikajude/nix,dezgeg/nix,dezgeg/nix,ehmry/nix,vcunat/nix,peti/nix,dtzWill/nix