nixos-rebuild-ng: remove conditionals for Nix < 2.18 (#433056)

  your password wrong, it will fail during activation (this can be improved

  though)

- When `--build-host` and `--target-host` are used together, we will use `nix

  copy` (or 2 `nix-copy-closure` if you're using Nix <2.18) instead of SSH'ing

  to build host and using `nix-copy-closure --to target-host`. The reason for

  this is documented in PR

  copy` instead of SSH'ing to build host and using

  `nix-copy-closure --to target-host`. The reason for this is documented in PR

  [#364698](https://github.com/NixOS/nixpkgs/pull/364698). If you do need the

  previous behavior, you can simulate it using `ssh build-host --

  nixos-rebuild-ng switch --target-host target-host`. If that is not the case,

  and there was a need to bootstrap a new version of Nix before evaluating the

  configuration (otherwise the new Nixpkgs version may have code that is only

  compatible with a newer version of Nix). Nixpkgs now has a policy to be

  compatible with Nix 2.3, and even if this is bumped as long we don't do

  compatible with Nix 2.18, and even if this is bumped as long we don't do

  drastic minimum version changes this should not be an issue. Also, the daemon

  itself always run with the previous version since even we can replace Nix in

  `PATH` (so Nix client), but we can't replace the daemon without switching to

*--use-substitutes*

	When set, nixos-rebuild will add *--use-substitutes* to each invocation

	of _nix-copy-closure_/_nix copy_. This will only affect the behavior of

	nixos-rebuild if *--target-host* or *--build-host* is also set. This is

	useful when the target-host connection to cache.nixos.org is faster than

	the connection between hosts.

	of _nix copy_. This will only affect the behavior of nixos-rebuild if

	*--target-host* or *--build-host* is also set. This is useful when the

	target-host connection to cache.nixos.org is faster than the connection

	between hosts.

*--sudo*

	When set, *nixos-rebuild* prefixes activation commands with sudo.

  # Very long tmp dirs lead to "too long for Unix domain socket"

  # SSH ControlPath errors. Especially macOS sets long TMPDIR paths.

  withTmpdir ? if stdenv.hostPlatform.isDarwin then "/tmp" else null,

  # This version is kind of arbitrary, we use some features that were

  # implemented in newer versions of Nix, but not necessary 2.18.

  # However, Lix is a fork of Nix 2.18, so this looks like a good version

  # to cut specific functionality.

  # ATTN: This currently doesn't disambiguate between Nix and Lix, so using this

  # in a conditional needs careful checking against both Nix implementations.

  withNix218 ? lib.versionAtLeast nix.version "2.18",

  # passthru.tests

  nixosTests,

  nixVersions,

  postPatch = ''

    substituteInPlace nixos_rebuild/constants.py \

      --subst-var-by executable ${executable} \

      --subst-var-by withNix218 ${lib.boolToString withNix218} \

      --subst-var-by withReexec ${lib.boolToString withReexec} \

      --subst-var-by withShellFiles ${lib.boolToString withShellFiles}

from typing import Final, assert_never

from . import nix, services

from .constants import EXECUTABLE, WITH_NIX_2_18, WITH_REEXEC, WITH_SHELL_FILES

from .constants import EXECUTABLE, WITH_REEXEC, WITH_SHELL_FILES

from .models import Action, BuildAttr, Flake, Profile

from .process import Remote

from .utils import LogFormatter

def execute(argv: list[str]) -> None:

    args, args_groups = parse_args(argv)

    if not WITH_NIX_2_18:

        logger.warning("you're using Nix <2.18, some features will not work correctly")

    common_flags = vars(args_groups["common_flags"])

    common_build_flags = common_flags | vars(args_groups["common_build_flags"])

    build_flags = common_build_flags | vars(args_groups["classic_build_flags"])

EXECUTABLE: Final[str] = "@executable@"

# Use either `== "true"` if the default (e.g.: `python -m nixos_rebuild`) is

# `False` or `!= "false"` if the default is `True`

WITH_NIX_2_18: Final[bool] = "@withNix218@" != "false"

WITH_REEXEC: Final[bool] = "@withReexec@" == "true"

WITH_SHELL_FILES: Final[bool] = "@withShellFiles@" == "true"