{ stdenv, fetchurl }: stdenv.mkDerivation { name = "which-2.20"; src = fetchurl { url = mirror://gnu/which/which-2.20.tar.gz; sha256 = "1y2p50zadb36izzh2zw4dm5hvdiydqf3qa88l8kav20dcmfbc5yl"; }; meta = { homepage = http://ftp.gnu.org/gnu/which/; }; }