Nixpacks Bug Report - Failed to solve process - Ruby install

[nerijunior]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

During nixpacks build there are some 404 references to NixOS/nixpkgs:

 > [ 4/21] RUN nix-env -if .nixpacks/nixpkgs-5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.nix && nix-collect-garbage -d:
0.375 warning: error: unable to download 'https://github.com/NixOS/nixpkgs/archive/5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.tar.gz': Couldn'
t resolve host name (6); retrying in 349 ms
0.724 warning: error: unable to download 'https://github.com/NixOS/nixpkgs/archive/5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.tar.gz': Couldn'
t resolve host name (6); retrying in 537 ms
1.262 warning: error: unable to download 'https://github.com/NixOS/nixpkgs/archive/5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.tar.gz': Couldn't resolve host name (6); retrying in 1012 ms
2.274 warning: error: unable to download 'https://github.com/NixOS/nixpkgs/archive/5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.tar.gz': Couldn't resolve host name (6); retrying in 2247 ms
4.523 error:
4.523        … while calling the 'import' builtin
4.523          at /app/.nixpacks/nixpkgs-5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.nix:3:12:
4.523             2|
4.523             3| let pkgs = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.tar.gz") { overlays = [  ]; };
4.523              |            ^
4.523             4| in with pkgs;
4.523
4.523        … while realising the context of a path
4.523
4.523        … while calling the 'fetchTarball' builtin
4.523          at /app/.nixpacks/nixpkgs-5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.nix:3:20:
4.523             2|
4.523             3| let pkgs = import (fetchTarball "https://github.com/NixOS/nixpkgs/archive/5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.tar.gz") { overlays = [  ]; };
4.523              |                    ^
4.523             4| in with pkgs;
4.523
4.523        error: unable to download 'https://github.com/NixOS/nixpkgs/archive/5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.tar.gz': Couldn't resolve host name (6)
------
Dockerfile:8
--------------------
   6 |
   7 |     COPY .nixpacks/nixpkgs-5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.nix .nixpacks/nixpkgs-5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.nix
   8 | >>> RUN nix-env -if .nixpacks/nixpkgs-5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.nix && nix-collect-garbage -d
   9 |     COPY .nixpacks/nixpkgs-bf744fe90419885eefced41b3e5ae442d732712d.nix .nixpacks/nixpkgs-bf744fe90419885eefced41b3e5ae442d732712d.nix
  10 |     RUN nix-env -if .nixpacks/nixpkgs-bf744fe90419885eefced41b3e5ae442d732712d.nix && nix-collect-garbage -d
--------------------
ERROR: failed to solve: process "/bin/bash -ol pipefail -c nix-env -if .nixpacks/nixpkgs-5148520bfab61f99fd25fb9ff7bfbb50dad3c9db.nix && nix-collect-garbage -d" did not complete successfully: exit code: 1
Error: Docker build failed

To reproduce

Use the standard rails Dockerfile and try to build it using nixpacks

Expected behavior

Pass all the installation and see image built.

Environment

Arch linux x86
nixpacks 1.21.2