{lib, pkgs} : let inherit (lib) nv nvs; in { # see new python derivations for example: # - development/interpreters/php_configurable/default.nix # - .. search composableDerivation in all-packages.nix .. # # You should be able to override anything you like easily # grep the mailinglist by title "python proposal" (dec 08) # -> http://mail.cs.uu.nl/pipermail/nix-dev/2008-December/001571.html # to see why this got complicated when using all its features composableDerivation = { # modify args before applying stdenv.mkDerivation, this should remove at least attrs removeAttrsBy f ? lib.prepareDerivationArgs, stdenv ? pkgs.stdenv, # initial set of arguments to be passed to stdenv.mkDerivation passing prepareDerivationArgs by default initial ? {}, # example func : (x: x // { x.buildInputs ++ ["foo"] }), but see mergeAttrByFunc which does this for you merge ? (lib.mergeOrApply lib.mergeAttrByFunc) }: lib.applyAndFun (args: stdenv.mkDerivation (f args)) merge (merge { inherit (lib) mergeAttrBy; } initial); # some utility functions # use this function to generate flag attrs for prepareDerivationArgs # E nable D isable F eature edf = {name, feat ? name, enable ? {}, disable ? {} , value ? ""}: nvs name { set = { configureFlags = ["--enable-${feat}${if value == "" then "" else "="}${value}"]; } // enable; unset = { configureFlags = ["--disable-${feat}"]; } // disable; }; # same for --with and --without- # W ith or W ithout F eature wwf = {name, feat ? name, enable ? {}, disable ? {}, value ? ""}: nvs name { set = { configureFlags = ["--with-${feat}${if value == "" then "" else "="}${value}"]; } // enable; unset = { configureFlags = ["--without-${feat}"]; } // disable; }; }