shell.nix:  warn about some common problems when entering the shell
shell.nix:  warn about some common problems when entering the shell

input-output-hk/daedalus,input-output-hk/daedalus,input-output-hk/daedalus,input-output-hk/daedalus,input-output-hk/daedalus,input-output-hk/daedalus