weird error

[connelly@fnord:/etc/nixos/fnord]$ nix eval nixpkgs.curl
trace: lib.zip is deprecated, use lib.zipAttrsWith instead
trace: `lib.nixpkgsVersion` is deprecated, use `lib.version` instead!
trace: `types.list` is deprecated; use `types.listOf` instead
trace: warning: types.string is deprecated because it quietly concatenates strings
trace: types.optionSet is deprecated; use types.submodule instead
trace: Warning: `showVal` is deprecated and will be removed in the next release, please use `traceSeqN`
trace: `mkStrict' is obsolete; use `mkOverride 0' instead.
error: anonymous function at /nix/store/05qzr9jbm20z4j8zjai1cnni756cjn68-nixos-20.03.2668.7c85b915892/nixos/pkgs/build-support/fetchurl/boot.nix:5:1 called with unexpected argument 'hash', at /nix/store/05qzr9jbm20z4j8zjai1cnni756cjn68-nixos-20.03.2668.7c85b915892/nixos/pkgs/development/interpreters/python/fetchpypi.nix:26:6
(use '--show-trace' to show detailed location information)