From c6a3a0f4f59bc6b2cc24aa1f4d6572906c95e9b9 Mon Sep 17 00:00:00 2001
From: Julien Moutinho <julm+nixpkgs@sourcephile.fr>
Date: Fri, 4 Sep 2020 06:53:00 +0200
Subject: [PATCH] nixos-rebuild: do not depend on nix.conf to activate flakes

---
 nixos/doc/manual/man-nixos-rebuild.xml         |  2 +-
 nixos/modules/installer/tools/nixos-rebuild.sh | 10 ++++++----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/nixos/doc/manual/man-nixos-rebuild.xml b/nixos/doc/manual/man-nixos-rebuild.xml
index f70f08a0f8a7..7dab5c69dfb5 100644
--- a/nixos/doc/manual/man-nixos-rebuild.xml
+++ b/nixos/doc/manual/man-nixos-rebuild.xml
@@ -521,7 +521,7 @@
 
    <varlistentry>
     <term>
-     <option>--flake</option> <replaceable>flake-uri</replaceable>[<replaceable>name</replaceable>]
+     <option>--flake</option> <replaceable>flake-uri</replaceable><optional>#<replaceable>name</replaceable></optional>
     </term>
     <listitem>
      <para>
diff --git a/nixos/modules/installer/tools/nixos-rebuild.sh b/nixos/modules/installer/tools/nixos-rebuild.sh
index 354274478a38..a139387479b7 100644
--- a/nixos/modules/installer/tools/nixos-rebuild.sh
+++ b/nixos/modules/installer/tools/nixos-rebuild.sh
@@ -17,6 +17,7 @@ showSyntax() {
 origArgs=("$@")
 extraBuildFlags=()
 lockFlags=()
+flakeFlags=()
 action=
 buildNix=1
 fast=
@@ -99,6 +100,7 @@ while [ "$#" -gt 0 ]; do
         ;;
       --flake)
         flake="$1"
+        flakeFlags=(--experimental-features 'nix-command flakes')
         shift 1
         ;;
       --recreate-lock-file|--no-update-lock-file|--no-write-lock-file|--no-registries|--commit-lock-file)
@@ -281,7 +283,7 @@ fi
 
 # Resolve the flake.
 if [[ -n $flake ]]; then
-    flake=$(nix flake info --json "${extraBuildFlags[@]}" "${lockFlags[@]}" -- "$flake" | jq -r .url)
+    flake=$(nix "${flakeFlags[@]}" flake info --json "${extraBuildFlags[@]}" "${lockFlags[@]}" -- "$flake" | jq -r .url)
 fi
 
 # Find configuration.nix and open editor instead of building.
@@ -290,7 +292,7 @@ if [ "$action" = edit ]; then
         NIXOS_CONFIG=${NIXOS_CONFIG:-$(nix-instantiate --find-file nixos-config)}
         exec "${EDITOR:-nano}" "$NIXOS_CONFIG"
     else
-        exec nix edit "${lockFlags[@]}" -- "$flake#$flakeAttr"
+        exec nix "${flakeFlags[@]}" edit "${lockFlags[@]}" -- "$flake#$flakeAttr"
     fi
     exit 1
 fi
@@ -416,7 +418,7 @@ if [ -z "$rollback" ]; then
             pathToConfig="$(nixBuild '<nixpkgs/nixos>' --no-out-link -A system "${extraBuildFlags[@]}")"
         else
             outLink=$tmpDir/result
-            nix build "$flake#$flakeAttr.config.system.build.toplevel" \
+            nix "${flakeFlags[@]}" build "$flake#$flakeAttr.config.system.build.toplevel" \
               "${extraBuildFlags[@]}" "${lockFlags[@]}" --out-link $outLink
             pathToConfig="$(readlink -f $outLink)"
         fi
@@ -426,7 +428,7 @@ if [ -z "$rollback" ]; then
         if [[ -z $flake ]]; then
             pathToConfig="$(nixBuild '<nixpkgs/nixos>' -A system -k "${extraBuildFlags[@]}")"
         else
-            nix build "$flake#$flakeAttr.config.system.build.toplevel" "${extraBuildFlags[@]}" "${lockFlags[@]}"
+            nix "${flakeFlags[@]}" build "$flake#$flakeAttr.config.system.build.toplevel" "${extraBuildFlags[@]}" "${lockFlags[@]}"
             pathToConfig="$(readlink -f ./result)"
         fi
     elif [ "$action" = build-vm ]; then