Devbox executes local flakes in pure mode, even if --pure is not specified.

[Vilsol]

What happened?

I have defined a local flake that has impurities, so it must be built using the --impure flag.

Running nix shell --impure works fine.

I would expect that unless --pure is passed to devbox shell it would build flakes as impure.

It seems that the issue is a missing --impure here: https://github.com/jetify-com/devbox/blob/main/internal/nix/command.go#L31

I would be willing to make a PR to add it if --pure is unspecified.

Steps to reproduce

1. Create the below flake and devbox config.
2. Run devbox shell

{
  inputs.nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";

  outputs = { self, nixpkgs }: {
    packages.x86_64-linux.hello = (
        builtins.trace builtins.currentSystem nixpkgs.legacyPackages.x86_64-linux.hello
    );

    packages.x86_64-linux.default = self.packages.x86_64-linux.hello;
  };
}

Command

shell

devbox.json

{
  "$schema": "https://raw.githubusercontent.com/jetify-com/devbox/0.11.0/.schema/devbox.schema.json",
  "packages": [
    "./#hello"
  ]
}

Devbox version

0.11.0

Nix version

nix (Nix) 2.18.2

What system does this bug occur on?

Linux (x86-64)

Debug logs

DEVBOX_DEBUG=1 devbox shell
2024/06/12 12:28:05 findProjectDir: path is
2024/06/12 12:28:05 finding devbox config in dir: /home/vilsol/tmp/devbox-flake-bug
2024/06/12 12:28:05 findProjectDir: path is
2024/06/12 12:28:05 finding devbox config in dir: /home/vilsol/tmp/devbox-flake-bug
2024/06/12 12:28:06 nix --version --debug output:
nix (Nix) 2.18.2
System type: x86_64-linux
Additional system types: i686-linux, x86_64-v1-linux, x86_64-v2-linux, x86_64-v3-linux
Features: gc, signed-caches
System configuration file: /etc/nix/nix.conf
User configuration files: /home/vilsol/.config/nix/nix.conf:/etc/xdg/nix/nix.conf:/home/vilsol/.local/share/flatpak/exports/etc/xdg/nix/nix.conf:/var/lib/flatpak/exports/etc/xdg/nix/nix.conf:/home/vilsol/.nix-profile/etc/xdg/nix/nix.conf:/nix/profile/etc/xdg/nix/nix.conf:/home/vilsol/.local/state/nix/profile/etc/xdg/nix/nix.conf:/etc/profiles/per-user/vilsol/etc/xdg/nix/nix.conf:/nix/var/nix/profiles/default/etc/xdg/nix/nix.conf:/run/current-system/sw/etc/xdg/nix/nix.conf:/nix/store/wbflpsk6a3k26pr9hrsl6bpvm80brxrr-gnome-settings-daemon-46.0/etc/xdg/nix/nix.conf
Store directory: /nix/store
State directory: /nix/var/nix
Data directory: /nix/store/fwrdsdlpqfhm6p4z9dk19vniw14mmq3s-nix-2.18.2/share
2024/06/12 12:28:06 findProjectDir: path is
2024/06/12 12:28:06 finding devbox config in dir: /home/vilsol/tmp/devbox-flake-bug
Info: Ensuring packages are installed.
Warning: Outputs for ./#hello are not in lockfile. Fetching store paths from nix, this may take a while
2024/06/12 12:28:06 Running cmd /run/current-system/sw/bin/nix path-info path:/home/vilsol/tmp/devbox-flake-bug#hello --json --impure --extra-experimental-features ca-derivations --option experimental-features nix-command flakes fetch-closure

2024/06/12 12:28:06 Running cmd /run/current-system/sw/bin/nix path-info --offline --json /nix/store/yh6x9ia5kxxw3w90vkb09vqgfvhb416k-hello-2.12.1 --extra-experimental-features ca-derivations --option experimental-features nix-command flakes fetch-closure
2024/06/12 12:28:06 running command: /run/current-system/sw/bin/nix search path:/home/vilsol/tmp/devbox-flake-bug#hello ^ --json --extra-experimental-features ca-derivations --option experimental-features nix-command flakes fetch-closure
Error: execute template flake_remove_nixpkgs.nix.tmpl: template: flake_remove_nixpkgs.nix.tmpl:69:22: executing "flake_remove_nixpkgs.nix.tmpl" at <.BuildInputs>: error calling BuildInputs: error searching for pkg path:/home/vilsol/tmp/devbox-flake-bug#hello: nix search exit code: 1, stderr: evaluating 'packages.x86_64-linux.hello'...
error:
       … while calling the 'trace' builtin

         at /nix/store/7nfpvfsrp9w1p7w8qsgfhkkxq0dpi3hk-source/flake.nix:6:9:

            5|     packages.x86_64-linux.hello = (
            6|         builtins.trace builtins.currentSystem nixpkgs.legacyPackages.x86_64-linux.hello
             |         ^
            7|     );

       error: attribute 'currentSystem' missing

       at /nix/store/7nfpvfsrp9w1p7w8qsgfhkkxq0dpi3hk-source/flake.nix:6:24:

            5|     packages.x86_64-linux.hello = (
            6|         builtins.trace builtins.currentSystem nixpkgs.legacyPackages.x86_64-linux.hello
             |                        ^
            7|     );
, original error: exit status 1

2024/06/12 12:28:06
ExecutionID:8aba4809395540b5a020c79db7354609
execute template flake_remove_nixpkgs.nix.tmpl: template: flake_remove_nixpkgs.nix.tmpl:69:22: executing "flake_remove_nixpkgs.nix.tmpl" at <.BuildInputs>: error calling BuildInputs: error searching for pkg path:/home/vilsol/tmp/devbox-flake-bug#hello: nix search exit code: 1, stderr: evaluating 'packages.x86_64-linux.hello'...
error:
       … while calling the 'trace' builtin

         at /nix/store/7nfpvfsrp9w1p7w8qsgfhkkxq0dpi3hk-source/flake.nix:6:9:

            5|     packages.x86_64-linux.hello = (
            6|         builtins.trace builtins.currentSystem nixpkgs.legacyPackages.x86_64-linux.hello
             |         ^
            7|     );

       error: attribute 'currentSystem' missing

       at /nix/store/7nfpvfsrp9w1p7w8qsgfhkkxq0dpi3hk-source/flake.nix:6:24:

            5|     packages.x86_64-linux.hello = (
            6|         builtins.trace builtins.currentSystem nixpkgs.legacyPackages.x86_64-linux.hello
             |                        ^
            7|     );
, original error: exit status 1
go.jetpack.io/devbox/internal/shellgen.writeFromTemplate
	go.jetpack.io/devbox/internal/shellgen/generate.go:92
go.jetpack.io/devbox/internal/shellgen.makeFlakeFile
	go.jetpack.io/devbox/internal/shellgen/generate.go:191
go.jetpack.io/devbox/internal/shellgen.GenerateForPrintEnv
	go.jetpack.io/devbox/internal/shellgen/generate.go:62
go.jetpack.io/devbox/internal/devbox.(*Devbox).recomputeState
	go.jetpack.io/devbox/internal/devbox/packages.go:338
go.jetpack.io/devbox/internal/devbox.(*Devbox).ensureStateIsUpToDate
	go.jetpack.io/devbox/internal/devbox/packages.go:278
go.jetpack.io/devbox/internal/devbox.(*Devbox).ensureStateIsUpToDateAndComputeEnv
	go.jetpack.io/devbox/internal/devbox/devbox.go:1015
go.jetpack.io/devbox/internal/devbox.(*Devbox).Shell
	go.jetpack.io/devbox/internal/devbox/devbox.go:207
go.jetpack.io/devbox/internal/boxcli.runShellCmd
	go.jetpack.io/devbox/internal/boxcli/shell.go:83
go.jetpack.io/devbox/internal/boxcli.shellCmd.func1
	go.jetpack.io/devbox/internal/boxcli/shell.go:36
github.com/spf13/cobra.(*Command).execute
	github.com/spf13/cobra@v1.8.0/command.go:983
github.com/spf13/cobra.(*Command).ExecuteC
	github.com/spf13/cobra@v1.8.0/command.go:1115
github.com/spf13/cobra.(*Command).Execute
	github.com/spf13/cobra@v1.8.0/command.go:1039
go.jetpack.io/devbox/internal/boxcli/midcobra.(*midcobraExecutable).Execute
	go.jetpack.io/devbox/internal/boxcli/midcobra/midcobra.go:61
go.jetpack.io/devbox/internal/boxcli.Execute
	go.jetpack.io/devbox/internal/boxcli/root.go:113
go.jetpack.io/devbox/internal/boxcli.Main
	go.jetpack.io/devbox/internal/boxcli/root.go:136
main.main
	go.jetpack.io/devbox/cmd/devbox/main.go:11
runtime.main
	runtime/proc.go:271
runtime.goexit
	runtime/asm_amd64.s:1695
2024/06/12 12:28:06 findProjectDir: path is
2024/06/12 12:28:06 finding devbox config in dir: /home/vilsol/tmp/devbox-flake-bug