From 2e1d60e197e2c5f5724424e2a24b58cca2631953 Mon Sep 17 00:00:00 2001
From: azuwis <azuwis@users.noreply.github.com>
Date: Mon, 1 Jun 2026 20:05:16 +0800
Subject: [PATCH 1/2] nixos-rebuild-ng: disable flake auto-detection when
 --file or --attr is used

When --file or --attr is explicitly passed, flake auto-detection should
not override the user's intent to use a non-flake configuration.
---
 pkgs/by-name/ni/nixos-rebuild-ng/nixos-rebuild.8.scd         | 5 ++++-
 .../ni/nixos-rebuild-ng/src/nixos_rebuild/__init__.py        | 4 ++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/pkgs/by-name/ni/nixos-rebuild-ng/nixos-rebuild.8.scd b/pkgs/by-name/ni/nixos-rebuild-ng/nixos-rebuild.8.scd
index 7ec6def5ca21..48a0fb8312d1 100644
--- a/pkgs/by-name/ni/nixos-rebuild-ng/nixos-rebuild.8.scd
+++ b/pkgs/by-name/ni/nixos-rebuild-ng/nixos-rebuild.8.scd
@@ -314,13 +314,16 @@ It must be one of the following:
 	be made using _nixos_ function in nixpkgs or importing and calling
 	nixos/lib/eval-config.nix from nixpkgs. If specified without *--attr*
 	option, builds the configuration from the top-level attribute set of the
-	file.
+	file. Using this option disables automatic flake detection, same as
+	*--no-flake*.
 
 *--attr* _attrPath_, *-A* _attrPath_
 	Build the NixOS system from a nix file and use the specified
 	attribute path from the file specified by the *--file* option.
 	If specified without *--file* option, uses _system.nix_ in current directory,
 	the system-wide _<nixos-system>_ file, or finally, /etc/nixos/system.nix.
+	Using this option disables automatic flake detection, same as
+	*--no-flake*.
 
 *--flake* _flake-uri[#name]_, *-F* _flake-uri[#name]_
 	Build the NixOS system from the specified flake. It defaults to the
diff --git a/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/__init__.py b/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/__init__.py
index c1ad2bde3d00..db0fe7a4ec5c 100644
--- a/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/__init__.py
+++ b/pkgs/by-name/ni/nixos-rebuild-ng/src/nixos_rebuild/__init__.py
@@ -329,6 +329,10 @@ def parse_args(
     if args.flake and (args.file or args.attr):
         parser.error("--flake cannot be used with --file or --attr")
 
+    if (args.file or args.attr) and args.flake is None:
+        # Disable flake auto-detection when --file or --attr is used
+        args.flake = False
+
     if args.store_path:
         if args.rollback:
             parser.error("--store-path and --rollback are mutually exclusive")

From b63a81166a10957b70d303c181adbec59c0f74f4 Mon Sep 17 00:00:00 2001
From: azuwis <azuwis@users.noreply.github.com>
Date: Thu, 4 Jun 2026 20:01:07 +0800
Subject: [PATCH 2/2] nixos-rebuild-ng: add tests for --file/--attr disabling
 flake auto-detection

---
 .../ni/nixos-rebuild-ng/src/tests/test_main.py   | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_main.py b/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_main.py
index 1e0e5779ac90..12bacafba8d5 100644
--- a/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_main.py
+++ b/pkgs/by-name/ni/nixos-rebuild-ng/src/tests/test_main.py
@@ -89,6 +89,22 @@ def test_parse_args() -> None:
     assert r_store_path.flake is False
     assert r_store_path.store_path == "/nix/store/foo"
 
+    # --file and --attr should disable flake auto-detection
+    r_file, _ = nr.parse_args(["nixos-rebuild", "switch", "--file", "foo.nix"])
+    assert r_file.flake is False
+    assert r_file.file == "foo.nix"
+
+    r_attr, _ = nr.parse_args(["nixos-rebuild", "switch", "--attr", "bar"])
+    assert r_attr.flake is False
+    assert r_attr.attr == "bar"
+
+    r_file_attr, _ = nr.parse_args(
+        ["nixos-rebuild", "switch", "--file", "foo.nix", "--attr", "bar"]
+    )
+    assert r_file_attr.flake is False
+    assert r_file_attr.file == "foo.nix"
+    assert r_file_attr.attr == "bar"
+
     r1, g1 = nr.parse_args(
         [
             "nixos-rebuild",