nix-shell/pure: keep environment variable SHLVL
nix-shell/pure: keep environment variable SHLVL
shlevy/nix,bennofs/nix,shlevy/nix,bennofs/nix,pikajude/nix,NixOS/nix,NixOS/nix,zimbatm/nix,peti/nix,vcunat/nix,peti/nix,dtzWill/nix,vcunat/nix,shlevy/nix,layus/nix,NixOS/nix,dtzWill/nix,peti/nix,dezgeg/nix,rycee/nix,ehmry/nix,rycee/nix,dtzWill/nix,rycee/nix,layus/nix,bennofs/nix,layus/nix,ehmry/nix,dezgeg/nix,dezgeg/nix,pikajude/nix,dtzWill/nix,NixOS/nix,ehmry/nix,peti/nix,pikajude/nix,zimbatm/nix,ehmry/nix,shlevy/nix,ehmry/nix,vcunat/nix,rycee/nix,zimbatm/nix,NixOS/nix,dezgeg/nix,dtzWill/nix,peti/nix,zimbatm/nix,dezgeg/nix,ehmry/nix,layus/nix,layus/nix,rycee/nix,shlevy/nix,bennofs/nix,vcunat/nix