import attrset via runCommand

flake.nix

@@ -44,7 +44,6 @@
           # https://nixos.org/manual/nixos/stable/#sec-option-declarations
           paths = mkOption {
             type = types.listOf types.path;
-            default = [];
             description = lib.mdDoc "One or more paths to Docker Compose files.";
           };
           runtime = mkOption {
@@ -87,13 +86,17 @@
             default = true;
             description = lib.mdDoc "Auto-start all containers.";
           };
+          output = mkOption {
+            type = types.anything;
+            description = lib.mdDoc "Output config.";
+          };
         };
-        config.compose2nix = mkIf (cfg.paths != []) {
-          # runCommandLocal ensures that we always build this derivation on the local machine.
-          # This allows us to circumvent the Nix binary cache and minimize the time spent outside
-          # of building the derivation.
-          # https://nixos.org/manual/nixpkgs/stable/#trivial-builder-runCommandLocal
-          output = pkgs.runCommandLocal "run-compose2nix" {
+        # runCommandLocal ensures that we always build this derivation on the local machine.
+        # This allows us to circumvent the Nix binary cache and minimize the time spent outside
+        # of building the derivation.
+        # https://nixos.org/manual/nixpkgs/stable/#trivial-builder-runCommandLocal
+        config = {
+          compose2nix.output = mkIf (cfg.paths != []) (import pkgs.runCommandLocal "compose2nix" {
             env = cfg.env;
             buildInputs = [ pkgs.compose2nix ];
           } ''
@@ -107,7 +110,7 @@
               -service_include='${cfg.serviceInclude}' \
               -auto_start=${cfg.autoStart} \
               -output=$out
-          '';
+          '');
         };
       };
     });

templates/main.nix.tmpl

@@ -1,5 +1,5 @@
 {{- $runtime := .Runtime | printf "%s" -}}
-{ pkgs, ... }:
+{ ... }:
 
 {
   # Runtime

testdata/TestDocker_WithProject_out.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ ... }:
 
 {
   # Runtime

testdata/TestDocker_out.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ ... }:
 
 {
   # Runtime

testdata/TestPodman_WithProject_out.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ ... }:
 
 {
   # Runtime

testdata/TestPodman_out.nix

@@ -1,4 +1,4 @@
-{ pkgs, ... }:
+{ ... }:
 
 {
   # Runtime