__structuredAttrs in Nix
In Nix 2 a new parameter to the derivation primitive was added. It changes how information is passed to the derivation builder. Current State In order to show how it changes the handling of parameters to derivation, the first example will show the current state with __structuredAttrs set to false and the stdenv.mkDerivation wrapper around derivation. All parameters are passed to the builder as environment variables, canonicalised by Nix in imitation of shell script conventions: