nix/eval-config.nix: fix custom configuration

When I introduced the global src attribute, I broke custom
configurations, since they wouldn't be passing that key in, and nor
should they.  To allow for non-customisable globals like src, we need
to separate them from config.  Here, I've modified eval-config.nix to
take a callback, so that it can provide multiple attributes, and
handle command line arguments itself so that doesn't need to be in
every entry point any more.  This gives us an interface similar to the
NixOS module system's, where a variety of globals are available that
can be pulled out of the passed attribute set as required, but with
the additional advantage that files are usable directly from
nix-build, and support command line arguments.

Signed-off-by: Alyssa Ross <hi@alyssa.is>
Fixes: 0149885 ("nix: centralise source cleaning")

26 files changed, 89 insertions, 89 deletions

diff --git a/Documentation/default.nix b/Documentation/default.nix
index a8f43ef..90f8e88 100644
--- a/Documentation/default.nix
+++ b/Documentation/default.nix
@@ -2,14 +2,14 @@
 # SPDX-FileCopyrightText: 2022 Unikie
 # SPDX-License-Identifier: MIT
 
-{ config ? import ../nix/eval-config.nix {} }: config.pkgs.callPackage (
+import ../nix/eval-config.nix ({ config, src, ... }: config.pkgs.callPackage (
 
 { lib, stdenvNoCC, jekyll, drawio-headless }:
 
 stdenvNoCC.mkDerivation {
   name = "spectrum-docs";
 
-  inherit (config) src;
+  inherit src;
   sourceRoot = "source/Documentation";
 
   buildPhase = ''
@@ -26,4 +26,4 @@ stdenvNoCC.mkDerivation {
 }
 ) {
   jekyll = import ./jekyll.nix { inherit config; };
-}
+})
diff --git a/Documentation/jekyll.nix b/Documentation/jekyll.nix
index 6f2866f..fe16186 100644
--- a/Documentation/jekyll.nix
+++ b/Documentation/jekyll.nix
@@ -1,7 +1,7 @@
 # SPDX-FileCopyrightText: 2022 Alyssa Ross <hi@alyssa.is>
 # SPDX-License-Identifier: MIT
 
-{ config ? import ../nix/eval-config.nix {} }: config.pkgs.callPackage (
+import ../nix/eval-config.nix ({ config, ... }: config.pkgs.callPackage (
 
 { bundlerApp }:
 
@@ -10,4 +10,4 @@ bundlerApp {
   gemdir = ./.;
   exes = [ "jekyll" ];
 }
-) { }
+) { })
diff --git a/host/initramfs/default.nix b/host/initramfs/default.nix
index 4d3c5ed..828ba5d 100644
--- a/host/initramfs/default.nix
+++ b/host/initramfs/default.nix
@@ -1,10 +1,13 @@
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 # SPDX-License-Identifier: MIT
 
-{ config ? import ../../nix/eval-config.nix {}
+import ../../nix/eval-config.nix (
+{ config, src
 , rootfs ? import ../rootfs { inherit config; }
+, ...
 }:
-let inherit (config) pkgs; in pkgs.callPackage (
+config.pkgs.callPackage (
+
 { lib, stdenvNoCC, makeModulesClosure, runCommand, writeReferencesToFile
 , pkgsStatic, busybox, cpio, microcodeAmd, microcodeIntel
 }:
@@ -80,7 +83,7 @@ in
 stdenvNoCC.mkDerivation {
   name = "initramfs";
 
-  inherit (config) src;
+  inherit src;
   sourceRoot = "source/host/initramfs";
 
   MICROCODE = microcode;
@@ -96,4 +99,4 @@ stdenvNoCC.mkDerivation {
 
   enableParallelBuilding = true;
 }
-) {}
+) {})
diff --git a/host/initramfs/shell.nix b/host/initramfs/shell.nix
index 48c1f81..5475737 100644
--- a/host/initramfs/shell.nix
+++ b/host/initramfs/shell.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../nix/eval-config.nix {} }:
+import ../../nix/eval-config.nix ({ config, ... } @ args:
 
 let
   inherit (config) pkgs;
@@ -23,4 +23,4 @@ initramfs.overrideAttrs ({ nativeBuildInputs ? [], ... }: {
   EXT_FS = extfs;
   KERNEL = "${rootfs.kernel}/${stdenv.hostPlatform.linux-kernel.target}";
   ROOT_FS = rootfs;
-})
+}))
diff --git a/host/rootfs/default.nix b/host/rootfs/default.nix
index ad997d1..acc0719 100644
--- a/host/rootfs/default.nix
+++ b/host/rootfs/default.nix
@@ -2,7 +2,8 @@
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 # SPDX-FileCopyrightText: 2022 Unikie
 
-{ config ? import ../../nix/eval-config.nix {} }: let inherit (config) pkgs; in
+import ../../nix/eval-config.nix (
+{ config, src, ... }: let inherit (config) pkgs; in
 pkgs.pkgsStatic.callPackage (
 
 { lib, stdenvNoCC, nixos, runCommand, writeReferencesToFile, s6-rc, tar2ext4
@@ -120,7 +121,7 @@ in
 stdenvNoCC.mkDerivation {
   name = "spectrum-rootfs";
 
-  inherit (config) src;
+  inherit src;
   sourceRoot = "source/host/rootfs";
 
   nativeBuildInputs = [ s6-rc tar2ext4 ];
@@ -142,4 +143,4 @@ stdenvNoCC.mkDerivation {
     platforms = platforms.linux;
   };
 }
-) {}
+) {})
diff --git a/host/rootfs/shell.nix b/host/rootfs/shell.nix
index ea8410a..94e84be 100644
--- a/host/rootfs/shell.nix
+++ b/host/rootfs/shell.nix
@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
 # SPDX-FileCopyrightText: 2022 Unikie
 
-{ config ? import ../../nix/eval-config.nix {} }:
+import ../../nix/eval-config.nix ({ config, ... } @ args:
 
 let
   rootfs = import ./. { inherit config; };
@@ -21,4 +21,4 @@ rootfs.overrideAttrs (
   EXT_FS = pkgsStatic.callPackage ../initramfs/extfs.nix { inherit config; };
   INITRAMFS = import ../initramfs { inherit config rootfs; };
   KERNEL = "${passthru.kernel}/${stdenv.hostPlatform.linux-kernel.target}";
-})
+}))
diff --git a/host/start-vm/default.nix b/host/start-vm/default.nix
index a7ca521..767a967 100644
--- a/host/start-vm/default.nix
+++ b/host/start-vm/default.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../nix/eval-config.nix {} }: config.pkgs.callPackage (
+import ../../nix/eval-config.nix ({ config, src, ... }: config.pkgs.callPackage (
 { lib, stdenv, meson, ninja, rustc }:
 
 let
@@ -11,11 +11,11 @@ in
 stdenv.mkDerivation {
   name = "start-vm";
 
-  inherit (config) src;
+  inherit src;
   sourceRoot = "source/host/start-vm";
 
   nativeBuildInputs = [ meson ninja rustc ];
 
   doCheck = true;
 }
-) { }
+) { })
diff --git a/host/start-vm/shell.nix b/host/start-vm/shell.nix
index 5192b76..cbc1fee 100644
--- a/host/start-vm/shell.nix
+++ b/host/start-vm/shell.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../nix/eval-config.nix {} }:
+import ../../nix/eval-config.nix ({ config, ... }:
 
 with config.pkgs;
 
@@ -10,4 +10,4 @@ with config.pkgs;
 
 {
   nativeBuildInputs = nativeBuildInputs ++ [ rustfmt ];
-})
+}))
diff --git a/img/app/default.nix b/img/app/default.nix
index 5386afc..7aa22ad 100644
--- a/img/app/default.nix
+++ b/img/app/default.nix
@@ -1,10 +1,8 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../nix/eval-config.nix {}
-, terminfo ? config.pkgs.foot.terminfo
-}:
-
+import ../../nix/eval-config.nix (
+{ config, src, terminfo ? config.pkgs.foot.terminfo, ... }:
 config.pkgs.pkgsStatic.callPackage (
 
 { lib, stdenvNoCC, runCommand, writeReferencesToFile, buildPackages
@@ -64,7 +62,7 @@ in
 stdenvNoCC.mkDerivation {
   name = "spectrum-appvm";
 
-  inherit (config) src;
+  inherit src;
   sourceRoot = "source/img/app";
 
   nativeBuildInputs = [ jq s6-rc tar2ext4 util-linux ];
@@ -83,4 +81,4 @@ stdenvNoCC.mkDerivation {
     platforms = platforms.linux;
   };
 }
-) {}
+) {})
diff --git a/img/app/shell.nix b/img/app/shell.nix
index 83dcd76..7a323aa 100644
--- a/img/app/shell.nix
+++ b/img/app/shell.nix
@@ -1,9 +1,8 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../nix/eval-config.nix {}
-, run ? ../../vm/app/catgirl.nix
-}:
+import ../../nix/eval-config.nix (
+{ config, run ? ../../vm/app/catgirl.nix, ... }:
 
 with config.pkgs;
 
@@ -21,4 +20,4 @@ with config.pkgs;
   shellHook = ''
     export RUN_IMG="$(printf "%s\n" "$runDef"/blk/run.img)"
   '';
-})
+}))
diff --git a/nix/checks.nix b/nix/checks.nix
index f399ef7..d5a40c0 100644
--- a/nix/checks.nix
+++ b/nix/checks.nix
@@ -1,9 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2022 Unikie
 
-{ config ? import ../nix/eval-config.nix {} }:
-
-{
+import ../nix/eval-config.nix ({ config, src, ... }: {
   recurseForDerivations = true;
 
   doc-links = config.pkgs.callPackage (
@@ -23,7 +21,7 @@
   reuse = config.pkgs.callPackage (
     { lib, runCommand, reuse }:
     runCommand "spectrum-reuse" {
-      inherit (config) src;
+      inherit src;
       nativeBuildInputs = [ reuse ];
     } ''
       reuse --root $src lint
@@ -34,7 +32,7 @@
   rustfmt = config.pkgs.callPackage (
     { lib, runCommand, rustfmt }:
     runCommand "spectrum-rustfmt" {
-      inherit (config) src;
+      inherit src;
       nativeBuildInputs = [ rustfmt ];
     } ''
       shopt -s globstar
@@ -46,7 +44,7 @@
   shellcheck = config.pkgs.callPackage (
     { lib, runCommand, shellcheck }:
     runCommand "spectrum-shellcheck" {
-      inherit (config) src;
+      inherit src;
       nativeBuildInputs = [ shellcheck ];
     } ''
       shopt -s globstar
@@ -54,4 +52,4 @@
       touch $out
     ''
   ) {};
-}
+})
diff --git a/nix/eval-config.nix b/nix/eval-config.nix
index 8ba7744..5164534 100644
--- a/nix/eval-config.nix
+++ b/nix/eval-config.nix
@@ -1,15 +1,20 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2022 Unikie
+# SPDX-FileCopyrightText: 2023 Alyssa Ross <hi@alyssa.is>
 
-{ config ?
-  let customPath = builtins.tryEval <spectrum-config>; in
+# The empty list of attribute set arguments is required, because
+# otherwise Nix will not pass arguments supplied on the command line
+# with --arg/--argstr.
+callback: { ... } @ args:
+
+callback (args // rec {
+  config = ({ pkgs ? import <nixpkgs> {} }: {
+    inherit pkgs;
+  }) args.config or (let customPath = builtins.tryEval <spectrum-config>; in
   if customPath.success then import customPath.value
   else if builtins.pathExists ../config.nix then import ../config.nix
-  else {}
-}:
-
-({ pkgs ? import <nixpkgs> {} }: {
-  inherit pkgs;
+  else {})
+;
 
-  src = import ./src.nix { inherit (pkgs) lib; };
-}) config
+  src = import ./src.nix { inherit (config.pkgs) lib; };
+})
diff --git a/release.nix b/release.nix
index 15471d0..707c86c 100644
--- a/release.nix
+++ b/release.nix
@@ -3,16 +3,16 @@
 
 # This file is built to populate the binary cache.
 
-# Set config = {} to disable implicitly reading config.nix, since
-# we'll want the result to be the same as on the binary cache.  If it
-# turns out there is a compelling reason to read the default config
-# here, we can reconsider this.
-{ config ? import nix/eval-config.nix { config = {}; } }:
-
-{
+import nix/eval-config.nix ({ config, ... }: {
   doc = import ./Documentation { inherit config; };
 
   checks = import nix/checks.nix { inherit config; };
 
   combined = import release/combined/run-vm.nix { inherit config; };
-}
+})
+
+# Set config = {} to disable implicitly reading config.nix, since
+# we'll want the result to be the same as on the binary cache.  If it
+# turns out there is a compelling reason to read the default config
+# here, we can reconsider this.
+{ config = {}; }
diff --git a/release/combined/default.nix b/release/combined/default.nix
index 2865376..7f7b3a2 100644
--- a/release/combined/default.nix
+++ b/release/combined/default.nix
@@ -3,7 +3,7 @@
 # SPDX-FileCopyrightText: 2021 Yureka <yuka@yuka.dev>
 # SPDX-FileCopyrightText: 2022 Unikie
 
-{ config ? import ../../nix/eval-config.nix {} }: with config.pkgs;
+import ../../nix/eval-config.nix ({ config, ... } @ args: with config.pkgs;
 
 let
   inherit (builtins) storeDir;
@@ -113,4 +113,4 @@ runCommand "spectrum-installer" {
   fillPartition $out 0 ${esp}
   fillPartition $out 1 ${rootfs}
   fillPartition $out 2 ${eosimages}
-''
+'')
diff --git a/release/combined/eosimages.nix b/release/combined/eosimages.nix
index 9f2ab10..b2dba13 100644
--- a/release/combined/eosimages.nix
+++ b/release/combined/eosimages.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../nix/eval-config.nix {} }: with config.pkgs;
+import ../../nix/eval-config.nix ({ config, ... }: with config.pkgs;
 
 runCommand "eosimages.img" {
   nativeBuildInputs = [ e2fsprogs tar2ext4 ];
@@ -15,4 +15,4 @@ runCommand "eosimages.img" {
   tar -chf $NIX_BUILD_TOP/eosimages.tar *
   tar2ext4 -i $NIX_BUILD_TOP/eosimages.tar -o $out
   e2label $out eosimages
-''
+'')
diff --git a/release/combined/run-vm.nix b/release/combined/run-vm.nix
index 2fc474e..10bd8bf 100644
--- a/release/combined/run-vm.nix
+++ b/release/combined/run-vm.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../nix/eval-config.nix {} }: with config.pkgs;
+import ../../nix/eval-config.nix ({ config, ... }: with config.pkgs;
 
 let
   image = import ./. { inherit config; };
@@ -22,4 +22,4 @@ writeShellScript "run-spectrum-installer-vm.sh" ''
     -drive file=${qemu_kvm}/share/qemu/edk2-${stdenv.hostPlatform.qemuArch}-code.fd,format=raw,if=pflash,readonly=true \
     -drive file=${image},id=drive1,format=raw,if=none,readonly=true \
     -drive file=/proc/self/fd/3,format=raw,if=virtio
-''
+'')
diff --git a/release/installer/default.nix b/release/installer/default.nix
index 0c57704..16a7d35 100644
--- a/release/installer/default.nix
+++ b/release/installer/default.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../nix/eval-config.nix {}, extraConfig ? {} }:
+import ../../nix/eval-config.nix ({ config, extraConfig ? {}, ... }:
 with config.pkgs;
 
 let
@@ -21,5 +21,4 @@ in
   ] ++ config.boot.kernelParams);
 
   store = writeReferencesToFile config.system.build.toplevel;
-}
-
+})
diff --git a/release/installer/run-vm.nix b/release/installer/run-vm.nix
index fe014f8..c42155b 100644
--- a/release/installer/run-vm.nix
+++ b/release/installer/run-vm.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../nix/eval-config.nix {} }:
+import ../../nix/eval-config.nix ({ config, ... }:
 
 let
   inherit (builtins) storeDir;
@@ -43,4 +43,4 @@ writeShellScript "run-spectrum-installer-vm.sh" ''
     -kernel ${installer.kernel} \
     -initrd ${installer.initramfs} \
     -append ${escapeShellArg installer.kernelParams}
-''
+'')
diff --git a/release/live/default.nix b/release/live/default.nix
index 66bba26..c36c34b 100644
--- a/release/live/default.nix
+++ b/release/live/default.nix
@@ -2,7 +2,8 @@
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 # SPDX-FileCopyrightText: 2022 Unikie
 
-{ config ? import ../../nix/eval-config.nix {} }: config.pkgs.callPackage (
+import ../../nix/eval-config.nix ({ config, src, ... }:
+config.pkgs.callPackage (
 
 { stdenvNoCC, cryptsetup, dosfstools, jq, mtools, util-linux, stdenv
 , systemd }:
@@ -22,7 +23,7 @@ in
 stdenvNoCC.mkDerivation {
   name = "spectrum-live.img";
 
-  inherit (config) src;
+  inherit src;
   sourceRoot = "source/release/live";
 
   nativeBuildInputs = [ cryptsetup dosfstools jq mtools util-linux ];
@@ -46,4 +47,4 @@ stdenvNoCC.mkDerivation {
 
   passthru = { inherit rootfs; };
 }
-) {}
+) {})
diff --git a/release/live/shell.nix b/release/live/shell.nix
index dcf2059..7cec144 100644
--- a/release/live/shell.nix
+++ b/release/live/shell.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../nix/eval-config.nix {} }:
+import ../../nix/eval-config.nix ({ config, ... }:
 
 with config.pkgs;
 
@@ -12,4 +12,4 @@ with config.pkgs;
 
     OVMF_CODE = "${qemu_kvm}/share/qemu/edk2-${stdenv.hostPlatform.qemuArch}-code.fd";
   }
-)
+))
diff --git a/shell.nix b/shell.nix
index 77deb2c..c249aa6 100644
--- a/shell.nix
+++ b/shell.nix
@@ -2,7 +2,7 @@
 # SPDX-FileCopyrightText: 2022 Unikie
 # SPDX-License-Identifier: MIT
 
-{ config ? import nix/eval-config.nix {} }: with config.pkgs;
+import nix/eval-config.nix ({ config, ... }: with config.pkgs;
 
 mkShell {
   nativeBuildInputs = [ b4 reuse rustfmt ];
@@ -13,4 +13,4 @@ mkShell {
     export "GIT_CONFIG_VALUE_''${GIT_CONFIG_COUNT:-0}"=https://spectrum-os.org/lists/archives/spectrum-devel/%s
     GIT_CONFIG_COUNT+=1
   '';
-}
+})
diff --git a/vm/app/catgirl.nix b/vm/app/catgirl.nix
index a4c05e3..f74acc9 100644
--- a/vm/app/catgirl.nix
+++ b/vm/app/catgirl.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../../nix/eval-config.nix {} }:
+import ../../nix/eval-config.nix ({ config, ... }:
 
 import ../make-vm.nix { inherit config; } {
   providers.net = [ "netvm" ];
@@ -14,4 +14,4 @@ import ../make-vm.nix { inherit config; } {
       ${catgirl}/bin/catgirl -h irc.libera.chat -j "#spectrum" -n $nick
     ''
   ) { };
-}
+})
diff --git a/vm/app/lynx.nix b/vm/app/lynx.nix
index 00d449e..d0b36a0 100644
--- a/vm/app/lynx.nix
+++ b/vm/app/lynx.nix
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../../nix/eval-config.nix {} }:
+import ../../nix/eval-config.nix ({ config, ... }:
 
 import ../make-vm.nix { inherit config; } {
   providers.net = [ "netvm" ];
@@ -12,4 +12,4 @@ import ../make-vm.nix { inherit config; } {
       ${lynx}/bin/lynx https://spectrum-os.org
     ''
   ) { };
-}
+})
diff --git a/vm/make-vm.nix b/vm/make-vm.nix
index 0d7c1f9..da3bdf7 100644
--- a/vm/make-vm.nix
+++ b/vm/make-vm.nix
@@ -1,9 +1,9 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../nix/eval-config.nix {} }:
+import ../nix/eval-config.nix ({ config, ... }:
 
 import ../vm-lib/make-vm.nix {
   inherit (config) pkgs;
   basePaths = (import ../img/app { inherit config; }).packagesSysroot;
-}
+})
diff --git a/vm/sys/net/default.nix b/vm/sys/net/default.nix
index 9d75728..a30f5f5 100644
--- a/vm/sys/net/default.nix
+++ b/vm/sys/net/default.nix
@@ -1,10 +1,8 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021-2022 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../../nix/eval-config.nix {}
-, terminfo ? config.pkgs.foot.terminfo
-}:
-
+import ../../../nix/eval-config.nix (
+{ config, src, terminfo ? config.pkgs.foot.terminfo, ... }:
 config.pkgs.pkgsStatic.callPackage (
 
 { lib, stdenvNoCC, runCommand, writeReferencesToFile, buildPackages
@@ -73,7 +71,7 @@ in
 stdenvNoCC.mkDerivation {
   name = "spectrum-netvm";
 
-  inherit (config) src;
+  inherit src;
   sourceRoot = "source/vm/sys/net";
 
   nativeBuildInputs = [ jq s6-rc tar2ext4 util-linux ];
@@ -94,4 +92,4 @@ stdenvNoCC.mkDerivation {
     platforms = platforms.linux;
   };
 }
-) {}
+) {})
diff --git a/vm/sys/net/shell.nix b/vm/sys/net/shell.nix
index 849920d..f298431 100644
--- a/vm/sys/net/shell.nix
+++ b/vm/sys/net/shell.nix
@@ -1,9 +1,7 @@
 # SPDX-License-Identifier: MIT
 # SPDX-FileCopyrightText: 2021 Alyssa Ross <hi@alyssa.is>
 
-{ config ? import ../../../nix/eval-config.nix {} }:
-
-with config.pkgs;
+import ../../../nix/eval-config.nix ({ config, ... }: with config.pkgs;
 
 (import ./. { inherit config; }).overrideAttrs (
 { passthru ? {}, nativeBuildInputs ? [], ... }:
@@ -12,4 +10,4 @@ with config.pkgs;
   nativeBuildInputs = nativeBuildInputs ++ [ cloud-hypervisor jq qemu_kvm reuse ];
 
   KERNEL = "${passthru.kernel.dev}/vmlinux";
-})
+}))