**Enable Nix experimental features system-wide and refactor Nix bootstrap config**

* Rename `config.sh` to `bootstrap_config.sh` to clearly separate installer bootstrap config from Nix system config
* Add `nix_conf_file.sh` to manage `/etc/nix/nix.conf` safely and idempotently
* Ensure `nix-command` and `flakes` are enabled without overwriting existing experimental features
* Invoke Nix config enforcement from `nix/init.sh` during root installation
* Update documentation and ShellCheck annotations accordingly
* Extend CLI git proxy to include `git status`

https://chatgpt.com/share/693d5c4a-bad0-800f-adaf-4719dd4ca377

scripts/nix/README.md

@@ -22,7 +22,7 @@ It is invoked during package installation (Arch/Debian/Fedora scriptlets) and ca
 
 The entry point sources small, focused modules from *scripts/nix/lib/*:
 
-- *config.sh* — configuration defaults (installer URL, retry timing)
+- *bootstrap_config.sh* — configuration defaults (installer URL, retry timing)
 - *detect.sh* — container detection helpers
 - *path.sh* — PATH adjustments and `nix` binary resolution helpers
 - *symlinks.sh* — user/global symlink helpers for stable `nix` discovery

scripts/nix/init.sh

@@ -1,21 +1,23 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-# shellcheck source=lib/config.sh
+# shellcheck source=lib/bootstrap_config.sh
 # shellcheck source=lib/detect.sh
 # shellcheck source=lib/path.sh
 # shellcheck source=lib/symlinks.sh
 # shellcheck source=lib/users.sh
 # shellcheck source=lib/install.sh
+# shellcheck source=lib/nix_conf_file.sh
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
-source "${SCRIPT_DIR}/lib/config.sh"
+source "${SCRIPT_DIR}/lib/bootstrap_config.sh"
 source "${SCRIPT_DIR}/lib/detect.sh"
 source "${SCRIPT_DIR}/lib/path.sh"
 source "${SCRIPT_DIR}/lib/symlinks.sh"
 source "${SCRIPT_DIR}/lib/users.sh"
 source "${SCRIPT_DIR}/lib/install.sh"
+source "${SCRIPT_DIR}/lib/nix_conf_file.sh"
 
 echo "[init-nix] Starting Nix initialization..."
 
@@ -26,6 +28,7 @@ main() {
     ensure_nix_on_path
 
     if [[ "${EUID:-0}" -eq 0 ]]; then
+      nixconf_ensure_experimental_features
       ensure_global_nix_symlinks "$(resolve_nix_bin 2>/dev/null || true)"
     else
       ensure_user_nix_symlink "$(resolve_nix_bin 2>/dev/null || true)"
@@ -106,6 +109,10 @@ main() {
   # -------------------------------------------------------------------------
   ensure_nix_on_path
 
+  if [[ "${EUID:-0}" -eq 0 ]]; then
+    nixconf_ensure_experimental_features
+  fi
+
   local nix_bin_post
   nix_bin_post="$(resolve_nix_bin 2>/dev/null || true)"
 

scripts/nix/lib/nix_conf_file.sh

@@ -0,0 +1,55 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Prevent double-sourcing
+if [[ -n "${PKGMGR_NIX_CONF_FILE_SH:-}" ]]; then
+  return 0
+fi
+PKGMGR_NIX_CONF_FILE_SH=1
+
+nixconf_file_path() {
+  echo "/etc/nix/nix.conf"
+}
+
+nixconf_ensure_experimental_features() {
+  local nix_conf want
+  nix_conf="$(nixconf_file_path)"
+  want="experimental-features = nix-command flakes"
+
+  mkdir -p /etc/nix
+
+  if [[ ! -f "${nix_conf}" ]]; then
+    echo "[nix-conf] Creating ${nix_conf} with: ${want}"
+    printf "%s\n" "${want}" >"${nix_conf}"
+    return 0
+  fi
+
+  if grep -qE '^\s*experimental-features\s*=' "${nix_conf}"; then
+    if grep -qE '^\s*experimental-features\s*=.*\bnix-command\b' "${nix_conf}" \
+      && grep -qE '^\s*experimental-features\s*=.*\bflakes\b' "${nix_conf}"; then
+      echo "[nix-conf] experimental-features already correct"
+      return 0
+    fi
+
+    echo "[nix-conf] Extending experimental-features in ${nix_conf}"
+
+    local current
+    current="$(grep -E '^\s*experimental-features\s*=' "${nix_conf}" | head -n1 | cut -d= -f2-)"
+    current="$(echo "${current}" | xargs)" # trim
+
+    # Build a merged feature string without duplicates (simple token set)
+    local merged="nix-command flakes"
+    local token
+    for token in ${current}; do
+      if [[ " ${merged} " != *" ${token} "* ]]; then
+        merged="${merged} ${token}"
+      fi
+    done
+
+    sed -i "s|^\s*experimental-features\s*=.*|experimental-features = ${merged}|" "${nix_conf}"
+    return 0
+  fi
+
+  echo "[nix-conf] Appending to ${nix_conf}: ${want}"
+  printf "\n%s\n" "${want}" >>"${nix_conf}"
+}