Added automatic Nix install if not present on system.

justfile

@@ -1,5 +1,9 @@
 scripts_dir := "scripts"
 
+# Check if Nix is installed, if not install it based on the platform
+install-nix: {{scripts_dir}}/install_nix.sh
+    @bash {{scripts_dir}}/install_nix.sh
+
 # Check if Rust is installed, if not install it
 install-rust:
     @if ! command -v rustc &> /dev/null; then \
@@ -28,4 +32,4 @@ install-cosmo:
         . {{scripts_dir}}/update_path.sh; \
     fi
 
-all: install-rust install-wasm-target install-openssl install-cosmo
+all: install-nix install-rust install-wasm-target install-openssl install-cosmo

scripts/install_nix.sh

@@ -0,0 +1,36 @@
+#!/bin/bash
+
+# Check if Nix is installed
+if ! command -v nix --help >/dev/null 2>&1; then
+  # Delete problematic backup files for bash and zsh if they exist
+  if [ -f "/etc/bash.bashrc.backup-before-nix" ]; then
+    sudo rm -f /etc/bash.bashrc.backup-before-nix
+  fi
+
+  if [ -f "/etc/bashrc.backup-before-nix" ]; then
+    sudo rm -f /etc/bashrc.backup-before-nix
+  fi
+
+  if [ -f "/etc/zshrc.backup-before-nix" ]; then
+    sudo rm -f /etc/zshrc.backup-before-nix
+  fi
+
+  # Determine the platform (Linux or macOS)
+  case `uname` in
+    Linux*)
+      echo "Error: Nix package manager is not installed. Installing Nix for Linux..."
+      sh <(curl -L https://nixos.org/nix/install) --daemon
+      ;;
+    Darwin*)
+      echo "Error: Nix package manager is not installed. Installing Nix for macOS..."
+      sh <(curl -L https://nixos.org/nix/install) --darwin-use-unencrypted-nix-store-volume
+      ;;
+    *)
+      echo "Unsupported platform for Nix installation"
+      exit 1;
+      ;;
+  esac
+
+else
+  echo "Nix package manager is already installed."
+fi