error: attribute 'defaultApp.x86_64-linux' should have type 'derivation'

[davidak]

I get this error on NixOS 22.11.3196.cd34d6ed7ba:

[davidak@gaming:~]$ nix run github:snowflakelinux/snow
error: attribute 'defaultApp.x86_64-linux' should have type 'derivation'

nix profile install github:snowflakelinux/snow works.