...
> [stage-0 4/9] RUN nix-env -if .nixpacks/nixpkgs-5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.nix && nix-collect-garbage -d:
23.29
23.29        (stack trace truncated; use '--show-trace' to show the full, detailed trace)
23.29
23.29        error: attribute 'rust' missing
23.29        at /nix/store/w3b3kragx9012wrjv9jb6amjz4i264fl-source/lib/rust-bin.nix:25:28:
23.29            24|
23.29            25|   toRustTarget = platform: platform.rust.rustcTarget;
23.29              |                            ^
23.29            26|
23.29        Did you mean rustc?