From 942a008e28cdd49ef58534a522364db8dcbb6237 Mon Sep 17 00:00:00 2001
From: figsoda <figsoda@pm.me>
Date: Mon, 29 May 2023 13:39:48 -0400
Subject: [PATCH 01/27] perInput: Make the default lazier

---
 modules/transposition.nix | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/modules/transposition.nix b/modules/transposition.nix
index 5ddfcd0..2cd5c52 100644
--- a/modules/transposition.nix
+++ b/modules/transposition.nix
@@ -65,10 +65,7 @@ in
       system: flake:
       mapAttrs
         (attrName: attrConfig: flake.${attrName}.${system})
-        (filterAttrs
-          (attrName: attrConfig: flake?${attrName}.${system})
-          config.transposition
-        );
+        config.transposition;
 
     perSystem = { ... }: {
       options =

From 40ee120dcc2c170d1180aa59bafbf046bb950706 Mon Sep 17 00:00:00 2001
From: figsoda <figsoda@pm.me>
Date: Mon, 29 May 2023 13:52:03 -0400
Subject: [PATCH 02/27] remove unused code

---
 all-modules.nix                 |  1 -
 dev/flake-module.nix            |  4 ++--
 dev/flake.nix                   |  2 +-
 extras/easyOverlay.nix          |  4 ++--
 extras/flakeModules.nix         |  4 +---
 flake.nix                       |  2 +-
 lib.nix                         | 23 +----------------------
 modules/apps.nix                |  7 +------
 modules/checks.nix              |  2 +-
 modules/debug.nix               |  3 ---
 modules/devShells.nix           |  2 +-
 modules/flake.nix               |  5 +----
 modules/formatter.nix           |  4 ++--
 modules/legacyPackages.nix      |  2 +-
 modules/moduleWithSystem.nix    |  2 +-
 modules/nixosConfigurations.nix |  2 +-
 modules/nixosModules.nix        |  4 +---
 modules/overlays.nix            |  4 ++--
 modules/packages.nix            |  2 +-
 modules/transposition.nix       |  6 +-----
 modules/withSystem.nix          |  6 ++----
 21 files changed, 24 insertions(+), 67 deletions(-)

diff --git a/all-modules.nix b/all-modules.nix
index 83d2bd0..0a9f38e 100644
--- a/all-modules.nix
+++ b/all-modules.nix
@@ -1,4 +1,3 @@
-{ lib, ... }:
 {
   imports = [
     ./modules/apps.nix
diff --git a/dev/flake-module.nix b/dev/flake-module.nix
index fa77f15..5ac60b9 100644
--- a/dev/flake-module.nix
+++ b/dev/flake-module.nix
@@ -13,7 +13,7 @@
     when.dayOfMonth = 1;
   };
 
-  perSystem = { config, self', inputs', pkgs, ... }: {
+  perSystem = { config, pkgs, ... }: {
 
     devShells.default = pkgs.mkShell {
       nativeBuildInputs = [
@@ -42,7 +42,7 @@
     # for repl exploration / debug
     config.config = config;
     options.mySystem = lib.mkOption { default = config.allSystems.${builtins.currentSystem}; };
-    config.effects = withSystem "x86_64-linux" ({ config, pkgs, hci-effects, ... }: {
+    config.effects = withSystem "x86_64-linux" ({ pkgs, hci-effects, ... }: {
       tests = {
         template = pkgs.callPackage ./tests/template.nix { inherit hci-effects; };
       };
diff --git a/dev/flake.nix b/dev/flake.nix
index b0af470..e6fc8e5 100644
--- a/dev/flake.nix
+++ b/dev/flake.nix
@@ -12,7 +12,7 @@
     hercules-ci-effects.url = "github:hercules-ci/hercules-ci-effects";
   };
 
-  outputs = { self, ... }:
+  outputs = { ... }:
     {
       # The dev tooling is in ./flake-module.nix
       # See comment at `inputs` above.
diff --git a/extras/easyOverlay.nix b/extras/easyOverlay.nix
index a29c890..679afd1 100644
--- a/extras/easyOverlay.nix
+++ b/extras/easyOverlay.nix
@@ -1,4 +1,4 @@
-toplevel@{ config, lib, flake-parts-lib, getSystemIgnoreWarning, ... }:
+toplevel@{ lib, flake-parts-lib, getSystemIgnoreWarning, ... }:
 let
   inherit (flake-parts-lib)
     mkPerSystemOption;
@@ -37,7 +37,7 @@ in
         };
       };
       config = {
-        _module.args.final = lib.mkDefault (pkgs.extend (toplevel.config.flake.overlays.default));
+        _module.args.final = lib.mkDefault (pkgs.extend toplevel.config.flake.overlays.default);
       };
     });
   };
diff --git a/extras/flakeModules.nix b/extras/flakeModules.nix
index 6468dcb..4da738e 100644
--- a/extras/flakeModules.nix
+++ b/extras/flakeModules.nix
@@ -1,10 +1,8 @@
-{ config, self, lib, flake-parts-lib, ... }:
+{ self, lib, flake-parts-lib, ... }:
 let
   inherit (lib)
-    filterAttrs
     mapAttrs
     mkOption
-    optionalAttrs
     types
     ;
   inherit (flake-parts-lib)
diff --git a/flake.nix b/flake.nix
index 5d1447b..190d8f2 100644
--- a/flake.nix
+++ b/flake.nix
@@ -5,7 +5,7 @@
     nixpkgs-lib.url = "github:NixOS/nixpkgs/nixos-unstable?dir=lib";
   };
 
-  outputs = { self, nixpkgs-lib, ... }: {
+  outputs = { nixpkgs-lib, ... }: {
     lib = import ./lib.nix { inherit (nixpkgs-lib) lib; };
     templates = {
       default = {
diff --git a/lib.nix b/lib.nix
index ae588c8..f99f0cc 100644
--- a/lib.nix
+++ b/lib.nix
@@ -28,27 +28,6 @@ let
     then maybeFlake._type == "flake"
     else maybeFlake ? inputs && maybeFlake ? outputs && maybeFlake ? sourceInfo;
 
-  # Polyfill functionTo to make sure it has type merging.
-  # Remove 2022-12
-  functionTo =
-    let sample = types.functionTo lib.types.str;
-    in
-    if sample.functor.wrapped._type or null == "option-type"
-    then types.functionTo
-    else
-      elemType: lib.mkOptionType {
-        name = "functionTo";
-        description = "function that evaluates to a(n) ${elemType.description}";
-        check = lib.isFunction;
-        merge = loc: defs:
-          fnArgs: (lib.mergeDefinitions (loc ++ [ "[function body]" ]) elemType (map (fn: { inherit (fn) file; value = fn.value fnArgs; }) defs)).mergedValue;
-        getSubOptions = prefix: elemType.getSubOptions (prefix ++ [ "[function body]" ]);
-        getSubModules = elemType.getSubModules;
-        substSubModules = m: functionTo (elemType.substSubModules m);
-        functor = (lib.defaultFunctor "functionTo") // { type = functionTo; wrapped = elemType; };
-        nestedTypes.elemType = elemType;
-      };
-
   # Polyfill https://github.com/NixOS/nixpkgs/pull/163617
   deferredModuleWith = lib.deferredModuleWith or (
     attrs@{ staticModules ? [ ] }: mkOptionType {
@@ -216,7 +195,7 @@ let
           } // optionalAttrs (toType != null) {
           type = toType;
         });
-        config = (mkAliasAndWrapDefsWithPriority (setAttrByPath to) fromOpt);
+        config = mkAliasAndWrapDefsWithPriority (setAttrByPath to) fromOpt;
       };
 
     # Helper function for importing while preserving module location. To be added
diff --git a/modules/apps.nix b/modules/apps.nix
index dcd5b09..0fd5d7c 100644
--- a/modules/apps.nix
+++ b/modules/apps.nix
@@ -1,4 +1,4 @@
-{ config, lib, flake-parts-lib, ... }:
+{ lib, flake-parts-lib, ... }:
 let
   inherit (lib)
     mkOption
@@ -17,11 +17,6 @@ let
   getExe = x:
     "${lib.getBin x}/bin/${x.meta.mainProgram or (throw ''Package ${x.name or ""} does not have meta.mainProgram set, so I don't know how to find the main executable. You can set meta.mainProgram, or pass the full path to executable, e.g. program = "''${pkg}/bin/foo"'')}";
 
-  getBin = x:
-    if !x?outputSpecified || !x.outputSpecified
-    then x.bin or x.out or x
-    else x;
-
   appType = lib.types.submodule {
     options = {
       type = mkOption {
diff --git a/modules/checks.nix b/modules/checks.nix
index d849c65..9e7ceae 100644
--- a/modules/checks.nix
+++ b/modules/checks.nix
@@ -1,4 +1,4 @@
-{ config, lib, flake-parts-lib, ... }:
+{ lib, flake-parts-lib, ... }:
 let
   inherit (lib)
     mkOption
diff --git a/modules/debug.nix b/modules/debug.nix
index 6436010..995f13b 100644
--- a/modules/debug.nix
+++ b/modules/debug.nix
@@ -10,9 +10,6 @@ let
   inherit (flake-parts-lib)
     mkPerSystemOption
     ;
-  inherit (builtins)
-    removeAttrs
-    ;
 
   mkDebugConfig = { config, options, extendModules }: config // {
     inherit config;
diff --git a/modules/devShells.nix b/modules/devShells.nix
index 6521fa8..d14e59e 100644
--- a/modules/devShells.nix
+++ b/modules/devShells.nix
@@ -1,4 +1,4 @@
-{ config, lib, flake-parts-lib, ... }:
+{ lib, flake-parts-lib, ... }:
 let
   inherit (lib)
     mkOption
diff --git a/modules/flake.nix b/modules/flake.nix
index 884b2de..012a6c9 100644
--- a/modules/flake.nix
+++ b/modules/flake.nix
@@ -1,10 +1,7 @@
-{ config, lib, ... }:
+{ lib, ... }:
 let
   inherit (lib)
-    filterAttrs
-    mapAttrs
     mkOption
-    optionalAttrs
     types
     ;
 in
diff --git a/modules/formatter.nix b/modules/formatter.nix
index 975e664..838b7cf 100644
--- a/modules/formatter.nix
+++ b/modules/formatter.nix
@@ -24,7 +24,7 @@ in
       };
     };
 
-    perSystem = mkPerSystemOption ({ config, ... }: {
+    perSystem = mkPerSystemOption {
       _file = ./formatter.nix;
       options = {
         formatter = mkOption {
@@ -35,7 +35,7 @@ in
           '';
         };
       };
-    });
+    };
   };
   config = {
     flake.formatter =
diff --git a/modules/legacyPackages.nix b/modules/legacyPackages.nix
index 36df4dd..fb17e14 100644
--- a/modules/legacyPackages.nix
+++ b/modules/legacyPackages.nix
@@ -1,4 +1,4 @@
-{ config, lib, flake-parts-lib, ... }:
+{ lib, flake-parts-lib, ... }:
 let
   inherit (lib)
     mkOption
diff --git a/modules/moduleWithSystem.nix b/modules/moduleWithSystem.nix
index 057399e..e5c7008 100644
--- a/modules/moduleWithSystem.nix
+++ b/modules/moduleWithSystem.nix
@@ -1,4 +1,4 @@
-{ config, lib, withSystem, ... }:
+{ withSystem, ... }:
 {
   config = {
     _module.args = {
diff --git a/modules/nixosConfigurations.nix b/modules/nixosConfigurations.nix
index c2ae8d6..7dc973b 100644
--- a/modules/nixosConfigurations.nix
+++ b/modules/nixosConfigurations.nix
@@ -1,4 +1,4 @@
-{ config, lib, flake-parts-lib, ... }:
+{ lib, flake-parts-lib, ... }:
 let
   inherit (lib)
     mkOption
diff --git a/modules/nixosModules.nix b/modules/nixosModules.nix
index 1d21f9e..34e205a 100644
--- a/modules/nixosModules.nix
+++ b/modules/nixosModules.nix
@@ -1,10 +1,8 @@
-{ config, self, lib, flake-parts-lib, ... }:
+{ self, lib, flake-parts-lib, ... }:
 let
   inherit (lib)
-    filterAttrs
     mapAttrs
     mkOption
-    optionalAttrs
     types
     ;
   inherit (flake-parts-lib)
diff --git a/modules/overlays.nix b/modules/overlays.nix
index 86fc457..a09e8f6 100644
--- a/modules/overlays.nix
+++ b/modules/overlays.nix
@@ -1,4 +1,4 @@
-{ config, lib, flake-parts-lib, ... }:
+{ lib, flake-parts-lib, ... }:
 let
   inherit (lib)
     mkOption
@@ -16,7 +16,7 @@ in
         # also update description when done
         type = types.lazyAttrsOf (types.uniq (types.functionTo (types.functionTo (types.lazyAttrsOf types.unspecified))));
         # This eta expansion exists for the sole purpose of making nix flake check happy.
-        apply = lib.mapAttrs (k: f: final: prev: f final prev);
+        apply = lib.mapAttrs (_k: f: final: prev: f final prev);
         default = { };
         example = lib.literalExpression or lib.literalExample ''
           {
diff --git a/modules/packages.nix b/modules/packages.nix
index dcb29eb..20f0071 100644
--- a/modules/packages.nix
+++ b/modules/packages.nix
@@ -1,4 +1,4 @@
-{ config, lib, flake-parts-lib, ... }:
+{ lib, flake-parts-lib, ... }:
 let
   inherit (lib)
     mkOption
diff --git a/modules/transposition.nix b/modules/transposition.nix
index 5ddfcd0..01ceb93 100644
--- a/modules/transposition.nix
+++ b/modules/transposition.nix
@@ -7,10 +7,6 @@ let
     mkOption
     types
     ;
-  inherit (flake-parts-lib)
-    mkSubmoduleOptions
-    mkPerSystemOption
-    ;
 
   transpositionModule = {
     options = {
@@ -70,7 +66,7 @@ in
           config.transposition
         );
 
-    perSystem = { ... }: {
+    perSystem = {
       options =
         mapAttrs
           (k: v: lib.mkOption { })
diff --git a/modules/withSystem.nix b/modules/withSystem.nix
index c6b0a16..161eece 100644
--- a/modules/withSystem.nix
+++ b/modules/withSystem.nix
@@ -1,8 +1,6 @@
-{ config, lib, flake-parts-lib, self, getSystem, ... }:
+{ lib, flake-parts-lib, getSystem, ... }:
 let
   inherit (lib)
-    genAttrs
-    mapAttrs
     mkOption
     types
     ;
@@ -12,7 +10,7 @@ let
 in
 {
   options = {
-    perSystem = mkPerSystemOption ({ config, options, system, specialArgs, ... }: {
+    perSystem = mkPerSystemOption ({ config, options, specialArgs, ... }: {
       _file = ./perSystem.nix;
       options = {
         allModuleArgs = mkOption {

From 6ae737878e164dcca72235196be1c0829aecbd79 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Tue, 30 May 2023 15:31:19 +0200
Subject: [PATCH 03/27] Test that packages is not strict in devShell

Discovered and solved by figsoda, see
https://github.com/hercules-ci/flake-parts/issues/160
---
 dev/tests/eval-tests.nix | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/dev/tests/eval-tests.nix b/dev/tests/eval-tests.nix
index e0dedae..437ee1a 100644
--- a/dev/tests/eval-tests.nix
+++ b/dev/tests/eval-tests.nix
@@ -35,6 +35,18 @@ rec {
       };
     };
 
+  packagesNonStrictInDevShells = mkFlake
+    { inputs.self = packagesNonStrictInDevShells; /* approximation */ }
+    {
+      systems = [ "a" "b" ];
+      perSystem = { system, self', ... }: {
+        packages.hello = pkg system "hello";
+        packages.default = self'.packages.hello;
+        devShells = throw "can't be strict in perSystem.devShells!";
+      };
+      flake.devShells = throw "can't be strict in devShells!";
+    };
+
   easyOverlay = mkFlake
     { inputs.self = { }; }
     {
@@ -148,6 +160,8 @@ rec {
 
     assert flakeModulesDisable.test123 == "option123";
 
+    assert packagesNonStrictInDevShells.packages.a.default == pkg "a" "hello";
+
     ok;
 
   result = runTests "ok";

From 6a6d2511659da22f1cdb1475322998c7ea8ad126 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Tue, 30 May 2023 15:43:56 +0200
Subject: [PATCH 04/27] Update ChangeLog

---
 ChangeLog.md | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/ChangeLog.md b/ChangeLog.md
index 02182ef..6103b3b 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,26 @@
+
+# 2023-05-30
+
+ - Fix a strictness issue in `perInput`, affecting `inputs'`, `self'`.
+   This has caused infinite recursions and potentially performance issues since
+   the introduction of these module arguments.
+
+# 2023-05-08
+
+ - Add [`importApply`](https://flake.parts/define-module-in-separate-file.html?highlight=importApply#importApply) for bringing variables from the flake scope into module files.
+
+ - Add `mkDeferredModuleOption` as a generic name for the implementation of `mkPerSystemOption`.
+
+# 2023-03-26
+
+ - Add preliminary support for `disabledModules` for modules exposed via the importable `flakeModules` module.
+   This requires a Nixpkgs of 2023-03-09 or newer.
+
+# 2023-01-05
+
+ - Add importable `easyOverlay` module for defining an overlay "easily" by reusing `perSystem`.
+   This is not for consuming overlays.
+
 # 2022-12-25
 
  - Added a new `flake.flakeModules` option so a flake can expose a module

From 542e3969499d184ba39fd7b3c201ead5bddfdd76 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Wed, 31 May 2023 16:31:11 +0200
Subject: [PATCH 05/27] Add lower bound to lib version

---
 flake.nix |  9 ++++++++-
 lib.nix   | 22 ++++++++++++++++++++--
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/flake.nix b/flake.nix
index 190d8f2..8b934f6 100644
--- a/flake.nix
+++ b/flake.nix
@@ -6,7 +6,14 @@
   };
 
   outputs = { nixpkgs-lib, ... }: {
-    lib = import ./lib.nix { inherit (nixpkgs-lib) lib; };
+    lib = import ./lib.nix {
+      inherit (nixpkgs-lib) lib;
+      # Extra info for version check message
+      revInfo =
+        if nixpkgs-lib?rev
+        then " (nixpkgs-lib.rev: ${nixpkgs-lib.rev})"
+        else "";
+    };
     templates = {
       default = {
         path = ./template/default;
diff --git a/lib.nix b/lib.nix
index f99f0cc..908ebfa 100644
--- a/lib.nix
+++ b/lib.nix
@@ -1,4 +1,8 @@
-{ lib }:
+{ lib
+  # Optionally a string with extra version info to be included in the error message
+  # in case is lib is out of date. Empty or starts with space.
+, revInfo ? ""
+}:
 let
   inherit (lib)
     mkOption
@@ -207,5 +211,19 @@ let
       lib.setDefaultModuleLocation modulePath (import modulePath staticArgs);
   };
 
+  # A best effort, lenient estimate. Please use a recent nixpkgs lib if you
+  # override it at all.
+  minVersion = "22.05";
+
 in
-flake-parts-lib
+
+if builtins.compareVersions lib.version minVersion <= 0
+then
+  abort ''
+    The nixpkgs-lib dependency of flake-parts was overridden but is too old.
+    The minimum supported version of nixpkgs-lib is ${minVersion},
+    but the actual version is ${lib.version}${revInfo}.
+  ''
+else
+
+  flake-parts-lib

From 70d1b51a85170b46b57a2ad62308501651daa5c1 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Wed, 31 May 2023 16:31:11 +0200
Subject: [PATCH 06/27] Add lower bound to lib version

---
 lib.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib.nix b/lib.nix
index 908ebfa..deebf70 100644
--- a/lib.nix
+++ b/lib.nix
@@ -217,7 +217,7 @@ let
 
 in
 
-if builtins.compareVersions lib.version minVersion <= 0
+if builtins.compareVersions lib.version minVersion < 0
 then
   abort ''
     The nixpkgs-lib dependency of flake-parts was overridden but is too old.

From 4c50ea36d7c757751ca1e409f5d96f46f7c7e04f Mon Sep 17 00:00:00 2001
From: Hercules CI Effects <hercules-ci[bot]@users.noreply.github.com>
Date: Thu, 1 Jun 2023 23:36:07 +0000
Subject: [PATCH 07/27] flake.lock: Update
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Flake lock file updates:

• Updated input 'nixpkgs-lib':
    'github:NixOS/nixpkgs/da45bf6ec7bbcc5d1e14d3795c025199f28e0de0?dir=lib' (2023-04-30)
  → 'github:NixOS/nixpkgs/4f53efe34b3a8877ac923b9350c874e3dcd5dc0a?dir=lib' (2023-05-31)
---
 flake.lock | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/flake.lock b/flake.lock
index 46c8d31..390baa9 100644
--- a/flake.lock
+++ b/flake.lock
@@ -3,11 +3,11 @@
     "nixpkgs-lib": {
       "locked": {
         "dir": "lib",
-        "lastModified": 1682879489,
-        "narHash": "sha256-sASwo8gBt7JDnOOstnps90K1wxmVfyhsTPPNTGBPjjg=",
+        "lastModified": 1685564631,
+        "narHash": "sha256-8ywr3AkblY4++3lIVxmrWZFzac7+f32ZEhH/A8pNscI=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "da45bf6ec7bbcc5d1e14d3795c025199f28e0de0",
+        "rev": "4f53efe34b3a8877ac923b9350c874e3dcd5dc0a",
         "type": "github"
       },
       "original": {

From ebc85327677ff69791e623bc90ba55a74f308737 Mon Sep 17 00:00:00 2001
From: sempruijs <sem@pruijs.net>
Date: Sat, 17 Jun 2023 21:11:44 +0200
Subject: [PATCH 08/27] Add aarch64-linux and x86_64-darwin systems to the
 default template

---
 template/default/flake.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/template/default/flake.nix b/template/default/flake.nix
index ab4bc55..929e34f 100644
--- a/template/default/flake.nix
+++ b/template/default/flake.nix
@@ -14,7 +14,7 @@
         # 3. Add here: foo.flakeModule
 
       ];
-      systems = [ "x86_64-linux" "aarch64-darwin" ];
+      systems = [ "x86_64-linux" "aarch64-linux" "aarch64-darwin" "x86_64-darwin" ];
       perSystem = { config, self', inputs', pkgs, system, ... }: {
         # Per-system attributes can be defined here. The self' and inputs'
         # module parameters provide easy access to attributes of the same

From 93292ab70aa11ffe2dcac783997b3d0dda7b8c25 Mon Sep 17 00:00:00 2001
From: Santiago Fraire <santiwilly@gmail.com>
Date: Thu, 15 Jun 2023 22:08:54 +0200
Subject: [PATCH 09/27] docs: add example for devShells

---
 modules/devShells.nix | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/modules/devShells.nix b/modules/devShells.nix
index d14e59e..5d672d6 100644
--- a/modules/devShells.nix
+++ b/modules/devShells.nix
@@ -3,6 +3,7 @@ let
   inherit (lib)
     mkOption
     types
+    literalExpression
     ;
   inherit (flake-parts-lib)
     mkTransposedPerSystemModule
@@ -17,6 +18,13 @@ mkTransposedPerSystemModule {
       An attribute set of packages to be used as shells.
       [`nix develop .#<name>`](https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-develop.html) will run `devShells.<name>`.
     '';
+    example = literalExpression ''
+    {
+      devShells.default = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [ wget bat git cargo ];
+        };
+    }
+    '';
   };
   file = ./devShells.nix;
 }

From a530cce7214492b40aff5270d90f8daac9511413 Mon Sep 17 00:00:00 2001
From: Santiago Fraire <santiwilly@gmail.com>
Date: Thu, 15 Jun 2023 22:13:02 +0200
Subject: [PATCH 10/27] docs: add examples folder

---
 examples/shell-environments/README.md | 28 +++++++++++++++++++++++++++
 examples/shell-environments/flake.nix | 22 +++++++++++++++++++++
 2 files changed, 50 insertions(+)
 create mode 100644 examples/shell-environments/README.md
 create mode 100644 examples/shell-environments/flake.nix

diff --git a/examples/shell-environments/README.md b/examples/shell-environments/README.md
new file mode 100644
index 0000000..a5d81e8
--- /dev/null
+++ b/examples/shell-environments/README.md
@@ -0,0 +1,28 @@
+# shell-environment
+
+This example shows how to create a shell environment which
+includes a diverse set of tools:
+
+```
+terraform
+wget
+bat
+git
+```
+
+You can search for more package in [nix packages](https://search.nixos.org/packages)
+
+## Usage
+
+The [`devShells` option](https://flake.parts/options/flake-parts.html#opt-perSystem.devShells) is used by the following command:
+
+```sh
+nix develop
+```
+
+You can have as many shells as you want, in this [flake.nix](./flake.nix), you also have
+`another_env` which includes `curl`. To open it:
+
+```sh
+nix develop .#another_env
+```
\ No newline at end of file
diff --git a/examples/shell-environments/flake.nix b/examples/shell-environments/flake.nix
new file mode 100644
index 0000000..298579c
--- /dev/null
+++ b/examples/shell-environments/flake.nix
@@ -0,0 +1,22 @@
+{
+  description = "Description for the project";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs = inputs@{ flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      systems = [ "x86_64-linux" "aarch64-darwin" "x86_64-darwin" ];
+      perSystem = { config, self', inputs', pkgs, system, ... }: {
+        devShells.default = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [ terraform wget bat git ];
+        };
+
+        devShells.another_env = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [ curl ];
+        };
+      };
+
+    };
+}

From fa681367b39ef399468a04bbc36a4a8068b934b5 Mon Sep 17 00:00:00 2001
From: Santiago Fraire <santiwilly@gmail.com>
Date: Thu, 15 Jun 2023 22:26:45 +0200
Subject: [PATCH 11/27] docs(README): add examples and projects

---
 README.md | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 98c67f6..e0fcebc 100644
--- a/README.md
+++ b/README.md
@@ -3,12 +3,12 @@
 
 _Core of a distributed framework for writing Nix Flakes._
 
-`flake-parts` provides the options that represent standard flake attributes 
+`flake-parts` provides the options that represent standard flake attributes
 and establishes a way of working with `system`.
 Opinionated features are provided by an ecosystem of modules that you can import.
 
 `flake-parts` _itself_ has the goal to be a minimal mirror of the Nix flake schema.
-Used by itself, it is very lightweight. 
+Used by itself, it is very lightweight.
 
 # Why Modules?
 
@@ -71,10 +71,22 @@ then slide `mkFlake` between your outputs function head and body,
 
 Now you can add the remaining module attributes like in the [the template](./template/default/flake.nix).
 
-# Example
+# Templates
 
 See [the template](./template/default/flake.nix).
 
+# Examples
+
+See the folder [examples/](./examples).
+
+# Projects using flake-parts
+
+- [nixd](https://github.com/nix-community/nixd/blob/main/flake.nix) (c++)
+- [hyperswitch](https://github.com/juspay/hyperswitch/blob/main/flake.nix) (rust)
+- [argo-workflows](https://github.com/argoproj/argo-workflows/blob/master/dev/nix/flake.nix) (go)
+- [nlp-service](https://github.com/recap-utr/nlp-service/blob/main/flake.nix) (python)
+- [emanote](https://github.com/srid/emanote/blob/master/flake.nix) (haskell)
+
 # Options Reference
 
 See [flake.parts options](https://flake.parts/options/flake-parts.html)

From 2cf8f2e746838cd94fcc58f7013aa77e5dd27b68 Mon Sep 17 00:00:00 2001
From: Santiago Fraire <santiwilly@gmail.com>
Date: Fri, 23 Jun 2023 19:31:29 +0200
Subject: [PATCH 12/27] docs: add lock to shell-environments

---
 examples/project-commands/flake.lock   |  0
 examples/shell-environments/README.md  |  3 ++
 examples/shell-environments/flake.lock | 63 ++++++++++++++++++++++++++
 3 files changed, 66 insertions(+)
 create mode 100644 examples/project-commands/flake.lock
 create mode 100644 examples/shell-environments/flake.lock

diff --git a/examples/project-commands/flake.lock b/examples/project-commands/flake.lock
new file mode 100644
index 0000000..e69de29
diff --git a/examples/shell-environments/README.md b/examples/shell-environments/README.md
index a5d81e8..de18ac7 100644
--- a/examples/shell-environments/README.md
+++ b/examples/shell-environments/README.md
@@ -14,6 +14,9 @@ You can search for more package in [nix packages](https://search.nixos.org/packa
 
 ## Usage
 
+> **Warning**
+> If you copy the flake.nix remember to add it to git, otherwise it won't work
+
 The [`devShells` option](https://flake.parts/options/flake-parts.html#opt-perSystem.devShells) is used by the following command:
 
 ```sh
diff --git a/examples/shell-environments/flake.lock b/examples/shell-environments/flake.lock
new file mode 100644
index 0000000..f1371b0
--- /dev/null
+++ b/examples/shell-environments/flake.lock
@@ -0,0 +1,63 @@
+{
+  "nodes": {
+    "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      },
+      "locked": {
+        "lastModified": 1685662779,
+        "narHash": "sha256-cKDDciXGpMEjP1n6HlzKinN0H+oLmNpgeCTzYnsA2po=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "71fb97f0d875fd4de4994dfb849f2c75e17eb6c3",
+        "type": "github"
+      },
+      "original": {
+        "id": "flake-parts",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1687412861,
+        "narHash": "sha256-Z/g0wbL68C+mSGerYS2quv9FXQ1RRP082cAC0Bh4vcs=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "e603dc5f061ca1d8a19b3ede6a8cf9c9fcba6cdc",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "dir": "lib",
+        "lastModified": 1685564631,
+        "narHash": "sha256-8ywr3AkblY4++3lIVxmrWZFzac7+f32ZEhH/A8pNscI=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "4f53efe34b3a8877ac923b9350c874e3dcd5dc0a",
+        "type": "github"
+      },
+      "original": {
+        "dir": "lib",
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-parts": "flake-parts",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

From 02b1bdb2fe921d5df93124943580af6af6d67c32 Mon Sep 17 00:00:00 2001
From: Santiago Fraire <santiwilly@gmail.com>
Date: Fri, 23 Jun 2023 19:31:43 +0200
Subject: [PATCH 13/27] docs: add commands example

---
 examples/project-commands/Hello.avdl  |  6 ++
 examples/project-commands/README.md   | 42 ++++++++++++
 examples/project-commands/flake.lock  | 95 +++++++++++++++++++++++++++
 examples/project-commands/flake.nix   | 37 +++++++++++
 examples/shell-environments/README.md |  6 +-
 5 files changed, 183 insertions(+), 3 deletions(-)
 create mode 100644 examples/project-commands/Hello.avdl
 create mode 100644 examples/project-commands/README.md
 create mode 100644 examples/project-commands/flake.nix

diff --git a/examples/project-commands/Hello.avdl b/examples/project-commands/Hello.avdl
new file mode 100644
index 0000000..2b3507f
--- /dev/null
+++ b/examples/project-commands/Hello.avdl
@@ -0,0 +1,6 @@
+protocol Hello {
+    record Hello {
+        string message;
+        int timestamp;
+    }
+}
\ No newline at end of file
diff --git a/examples/project-commands/README.md b/examples/project-commands/README.md
new file mode 100644
index 0000000..2f459f4
--- /dev/null
+++ b/examples/project-commands/README.md
@@ -0,0 +1,42 @@
+# project-commands
+
+> **Warning**
+> If you copy the flake.nix remember to `git add [-N|--intent-to-add] flake.nix`, otherwise it won't work
+
+This example shows how to create scripts for your project, by leveraging [mission-control](https://github.com/Platonic-Systems/mission-control)
+
+This is a **potential** alternative to:
+
+- Using a `Makefile` to manage your project's scripts
+- Using the popular [Scripts To Rule Them All](https://github.com/github/scripts-to-rule-them-all) approach (having a `scripts/` folder)
+- Using a `bin/` folder
+
+## Explanation
+
+In this example we use the [avro-tools](https://avro.apache.org/) to convert our scripts from `.avdl` to `.avsc`.
+
+You don't need to know anything about avro to understand mission-control and use this example (that's nix baby 🚀).
+
+When setting up [mission-control](https://github.com/Platonic-Systems/mission-control), we add
+one script called `build`. Because of `wrapperName = "run";`, once we open the shell created by nix,
+the commands will be listed as `run build`.
+
+mission-control depends on flake-root, which also exposes the helpful `$FLAKE_ROOT` variable.
+
+After creating the scripts, we need to pass the newly created scripts to the desired shell, in this example we use the default shell.
+
+## Usage
+
+Run:
+
+```sh
+nix develop
+```
+
+And mission-control will print in the new shell the available commands (you should see only one).
+
+Try running
+
+```sh
+run build
+```
diff --git a/examples/project-commands/flake.lock b/examples/project-commands/flake.lock
index e69de29..6179e83 100644
--- a/examples/project-commands/flake.lock
+++ b/examples/project-commands/flake.lock
@@ -0,0 +1,95 @@
+{
+  "nodes": {
+    "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      },
+      "locked": {
+        "lastModified": 1685662779,
+        "narHash": "sha256-cKDDciXGpMEjP1n6HlzKinN0H+oLmNpgeCTzYnsA2po=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "71fb97f0d875fd4de4994dfb849f2c75e17eb6c3",
+        "type": "github"
+      },
+      "original": {
+        "id": "flake-parts",
+        "type": "indirect"
+      }
+    },
+    "flake-root": {
+      "locked": {
+        "lastModified": 1680964220,
+        "narHash": "sha256-dIdTYcf+KW9a4pKHsEbddvLVSfR1yiAJynzg2x0nfWg=",
+        "owner": "srid",
+        "repo": "flake-root",
+        "rev": "f1c0b93d05bdbea6c011136ba1a135c80c5b326c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "srid",
+        "repo": "flake-root",
+        "type": "github"
+      }
+    },
+    "mission-control": {
+      "locked": {
+        "lastModified": 1683658484,
+        "narHash": "sha256-JkGnWyYZxOnyOhztrxLSqaod6+O/3rRypq0dAqA/zn0=",
+        "owner": "Platonic-Systems",
+        "repo": "mission-control",
+        "rev": "a0c93bd764a3c25e6999397e9f5f119c1b124e38",
+        "type": "github"
+      },
+      "original": {
+        "owner": "Platonic-Systems",
+        "repo": "mission-control",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1687502512,
+        "narHash": "sha256-dBL/01TayOSZYxtY4cMXuNCBk8UMLoqRZA+94xiFpJA=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "3ae20aa58a6c0d1ca95c9b11f59a2d12eebc511f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "dir": "lib",
+        "lastModified": 1685564631,
+        "narHash": "sha256-8ywr3AkblY4++3lIVxmrWZFzac7+f32ZEhH/A8pNscI=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "4f53efe34b3a8877ac923b9350c874e3dcd5dc0a",
+        "type": "github"
+      },
+      "original": {
+        "dir": "lib",
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-parts": "flake-parts",
+        "flake-root": "flake-root",
+        "mission-control": "mission-control",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/examples/project-commands/flake.nix b/examples/project-commands/flake.nix
new file mode 100644
index 0000000..a8e070d
--- /dev/null
+++ b/examples/project-commands/flake.nix
@@ -0,0 +1,37 @@
+{
+  description = "Description for the project";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+    mission-control.url = "github:Platonic-Systems/mission-control";
+    flake-root.url = "github:srid/flake-root";
+  };
+
+  outputs = inputs@{ flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      imports = [
+        inputs.mission-control.flakeModule
+        inputs.flake-root.flakeModule
+      ];
+      systems = [ "x86_64-linux" "aarch64-darwin" "x86_64-darwin" ];
+      perSystem = { config, self', inputs', pkgs, system, ... }: {
+        devShells.default = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [ avro-tools ];
+          inputsFrom = [ config.mission-control.devShell config.flake-root.devShell ];
+        };
+        mission-control = {
+          wrapperName = "run";
+          scripts = {
+            build = {
+              description = "convert files from .avdl to .avsc";
+              exec = ''
+                avro-tools idl2schemata "$FLAKE_ROOT/Hello.avdl" .
+              '';
+              category = "Development";
+            };
+          };
+        };
+      };
+    };
+}
diff --git a/examples/shell-environments/README.md b/examples/shell-environments/README.md
index de18ac7..5921bab 100644
--- a/examples/shell-environments/README.md
+++ b/examples/shell-environments/README.md
@@ -1,5 +1,8 @@
 # shell-environment
 
+> **Warning**
+> If you copy the flake.nix remember to `git add [-N|--intent-to-add] flake.nix`, otherwise it won't work
+
 This example shows how to create a shell environment which
 includes a diverse set of tools:
 
@@ -14,9 +17,6 @@ You can search for more package in [nix packages](https://search.nixos.org/packa
 
 ## Usage
 
-> **Warning**
-> If you copy the flake.nix remember to add it to git, otherwise it won't work
-
 The [`devShells` option](https://flake.parts/options/flake-parts.html#opt-perSystem.devShells) is used by the following command:
 
 ```sh

From 8fd103c90b37ef913577c1696f1c2011b3bfa704 Mon Sep 17 00:00:00 2001
From: Santiago Fraire <santiwilly@gmail.com>
Date: Sat, 24 Jun 2023 08:22:56 +0200
Subject: [PATCH 14/27] docs: add troubleshooting to shell-environemnts

---
 examples/shell-environments/README.md | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/examples/shell-environments/README.md b/examples/shell-environments/README.md
index 5921bab..271c908 100644
--- a/examples/shell-environments/README.md
+++ b/examples/shell-environments/README.md
@@ -6,7 +6,7 @@
 This example shows how to create a shell environment which
 includes a diverse set of tools:
 
-```
+```sh
 terraform
 wget
 bat
@@ -28,4 +28,25 @@ You can have as many shells as you want, in this [flake.nix](./flake.nix), you a
 
 ```sh
 nix develop .#another_env
-```
\ No newline at end of file
+```
+
+## Troubleshooting
+
+### My shell has changed
+
+There 2 possible solutions:
+
+First, using [direnv](https://direnv.net/) to manage your dev environments. See [direnv-guide](https://haskell.flake.page/direnv). This is the recommended approach.
+
+Second is a simple-unreliable hack, which is adding a `shellHook` to `devShells`
+
+```nix
+devShells.default = pkgs.mkShell {
+    shellHook = ''
+    exec $SHELL
+    '';
+};
+```
+
+You might get a lot different issues, use it at your own risk.
+

From 1a3b8642614f33d296c58d63456c57b7d0606ab2 Mon Sep 17 00:00:00 2001
From: Santiago Fraire <santiwilly@gmail.com>
Date: Sat, 24 Jun 2023 08:36:14 +0200
Subject: [PATCH 15/27] docs: make documentation visible right away

---
 README.md | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/README.md b/README.md
index e0fcebc..d90011f 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,12 @@ Opinionated features are provided by an ecosystem of modules that you can import
 `flake-parts` _itself_ has the goal to be a minimal mirror of the Nix flake schema.
 Used by itself, it is very lightweight.
 
+---
+
+**Documentation**: [flake.parts](https://flake.parts)
+
+---
+
 # Why Modules?
 
 Flakes are configuration. The module system lets you refactor configuration
@@ -90,7 +96,3 @@ See the folder [examples/](./examples).
 # Options Reference
 
 See [flake.parts options](https://flake.parts/options/flake-parts.html)
-
-# Documentation
-
-See [flake.parts](https://flake.parts)

From 6f53e9012c981d7e1e5bcf5bc17690af3f0d9560 Mon Sep 17 00:00:00 2001
From: Santiago Fraire <santiwilly@gmail.com>
Date: Mon, 26 Jun 2023 09:14:11 +0200
Subject: [PATCH 16/27] docs: update to comments

---
 README.md                             |  2 +-
 examples/project-commands/README.md   |  6 +++---
 examples/shell-environments/README.md | 13 ++++++++-----
 examples/shell-environments/flake.nix |  2 +-
 modules/devShells.nix                 |  8 ++++----
 5 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/README.md b/README.md
index d90011f..7d86a0a 100644
--- a/README.md
+++ b/README.md
@@ -83,7 +83,7 @@ See [the template](./template/default/flake.nix).
 
 # Examples
 
-See the folder [examples/](./examples).
+See the [examples/](./examples) directory.
 
 # Projects using flake-parts
 
diff --git a/examples/project-commands/README.md b/examples/project-commands/README.md
index 2f459f4..a75b9d6 100644
--- a/examples/project-commands/README.md
+++ b/examples/project-commands/README.md
@@ -8,14 +8,14 @@ This example shows how to create scripts for your project, by leveraging [missio
 This is a **potential** alternative to:
 
 - Using a `Makefile` to manage your project's scripts
-- Using the popular [Scripts To Rule Them All](https://github.com/github/scripts-to-rule-them-all) approach (having a `scripts/` folder)
-- Using a `bin/` folder
+- Using the popular [Scripts To Rule Them All](https://github.com/github/scripts-to-rule-them-all); a naming convention for a `scripts/` directory
+- Using a `bin/` directory
 
 ## Explanation
 
 In this example we use the [avro-tools](https://avro.apache.org/) to convert our scripts from `.avdl` to `.avsc`.
 
-You don't need to know anything about avro to understand mission-control and use this example (that's nix baby 🚀).
+You don't need to know anything about avro to understand mission-control and use this example (that's Nix baby 🚀).
 
 When setting up [mission-control](https://github.com/Platonic-Systems/mission-control), we add
 one script called `build`. Because of `wrapperName = "run";`, once we open the shell created by nix,
diff --git a/examples/shell-environments/README.md b/examples/shell-environments/README.md
index 271c908..4423ed4 100644
--- a/examples/shell-environments/README.md
+++ b/examples/shell-environments/README.md
@@ -10,10 +10,10 @@ includes a diverse set of tools:
 terraform
 wget
 bat
-git
+nixpkgs-fmt
 ```
 
-You can search for more package in [nix packages](https://search.nixos.org/packages)
+You can search for more packages in [nix packages](https://search.nixos.org/packages)
 
 ## Usage
 
@@ -32,7 +32,9 @@ nix develop .#another_env
 
 ## Troubleshooting
 
-### My shell has changed
+### I get bash instead of my shell
+
+`nix develop` was designed for Nixpkgs stdenv, which uses bash, so that you can troubleshoot a Nix build with it. If you use a different shell, you'll want to get just the variables instead.
 
 There 2 possible solutions:
 
@@ -42,11 +44,12 @@ Second is a simple-unreliable hack, which is adding a `shellHook` to `devShells`
 
 ```nix
 devShells.default = pkgs.mkShell {
-    shellHook = ''
+  shellHook = ''
     exec $SHELL
-    '';
+  '';
 };
 ```
 
 You might get a lot different issues, use it at your own risk.
 
+Lastly, there's `nix print-dev-env` which returns the variables - in case you're feeling adventurous, because this is far from a complete solution. See `nix print-dev-env --help`.
diff --git a/examples/shell-environments/flake.nix b/examples/shell-environments/flake.nix
index 298579c..25b4045 100644
--- a/examples/shell-environments/flake.nix
+++ b/examples/shell-environments/flake.nix
@@ -10,7 +10,7 @@
       systems = [ "x86_64-linux" "aarch64-darwin" "x86_64-darwin" ];
       perSystem = { config, self', inputs', pkgs, system, ... }: {
         devShells.default = pkgs.mkShell {
-          nativeBuildInputs = with pkgs; [ terraform wget bat git ];
+          nativeBuildInputs = with pkgs; [ terraform wget bat nixpkgs-fmt ];
         };
 
         devShells.another_env = pkgs.mkShell {
diff --git a/modules/devShells.nix b/modules/devShells.nix
index 5d672d6..c0cc6c5 100644
--- a/modules/devShells.nix
+++ b/modules/devShells.nix
@@ -19,11 +19,11 @@ mkTransposedPerSystemModule {
       [`nix develop .#<name>`](https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-develop.html) will run `devShells.<name>`.
     '';
     example = literalExpression ''
-    {
-      devShells.default = pkgs.mkShell {
-          nativeBuildInputs = with pkgs; [ wget bat git cargo ];
+      {
+        default = pkgs.mkShell {
+          nativeBuildInputs = with pkgs; [ wget bat cargo ];
         };
-    }
+      }
     '';
   };
   file = ./devShells.nix;

From 8af754293ae635a0ffad2923398a60a99ade02f6 Mon Sep 17 00:00:00 2001
From: Hercules CI Effects <hercules-ci[bot]@users.noreply.github.com>
Date: Sat, 1 Jul 2023 23:35:49 +0000
Subject: [PATCH 17/27] flake.lock: Update
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Flake lock file updates:

• Updated input 'nixpkgs-lib':
    'github:NixOS/nixpkgs/4f53efe34b3a8877ac923b9350c874e3dcd5dc0a?dir=lib' (2023-05-31)
  → 'github:NixOS/nixpkgs/4bc72cae107788bf3f24f30db2e2f685c9298dc9?dir=lib' (2023-06-29)
---
 flake.lock | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/flake.lock b/flake.lock
index 390baa9..5b3d2cc 100644
--- a/flake.lock
+++ b/flake.lock
@@ -3,11 +3,11 @@
     "nixpkgs-lib": {
       "locked": {
         "dir": "lib",
-        "lastModified": 1685564631,
-        "narHash": "sha256-8ywr3AkblY4++3lIVxmrWZFzac7+f32ZEhH/A8pNscI=",
+        "lastModified": 1688049487,
+        "narHash": "sha256-100g4iaKC9MalDjUW9iN6Jl/OocTDtXdeAj7pEGIRh4=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "4f53efe34b3a8877ac923b9350c874e3dcd5dc0a",
+        "rev": "4bc72cae107788bf3f24f30db2e2f685c9298dc9",
         "type": "github"
       },
       "original": {

From 7910deccec23fb2f49b0f3703aa2fee58e7173cf Mon Sep 17 00:00:00 2001
From: Robert Hensing <roberth@users.noreply.github.com>
Date: Tue, 4 Jul 2023 12:19:47 +0200
Subject: [PATCH 18/27] examples/shell-environments/README: typo

---
 examples/shell-environments/README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/shell-environments/README.md b/examples/shell-environments/README.md
index 4423ed4..0f72c1c 100644
--- a/examples/shell-environments/README.md
+++ b/examples/shell-environments/README.md
@@ -36,7 +36,7 @@ nix develop .#another_env
 
 `nix develop` was designed for Nixpkgs stdenv, which uses bash, so that you can troubleshoot a Nix build with it. If you use a different shell, you'll want to get just the variables instead.
 
-There 2 possible solutions:
+There are 3 possible solutions:
 
 First, using [direnv](https://direnv.net/) to manage your dev environments. See [direnv-guide](https://haskell.flake.page/direnv). This is the recommended approach.
 

From 85c7a895ebd6c8c7b41fc668169208f194ffc9d1 Mon Sep 17 00:00:00 2001
From: Hercules CI Effects <hercules-ci[bot]@users.noreply.github.com>
Date: Tue, 1 Aug 2023 23:36:20 +0000
Subject: [PATCH 19/27] flake.lock: Update
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Flake lock file updates:

• Updated input 'nixpkgs-lib':
    'github:NixOS/nixpkgs/4bc72cae107788bf3f24f30db2e2f685c9298dc9?dir=lib' (2023-06-29)
  → 'github:NixOS/nixpkgs/9e1960bc196baf6881340d53dccb203a951745a2?dir=lib' (2023-08-01)
---
 flake.lock | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/flake.lock b/flake.lock
index 5b3d2cc..f31d601 100644
--- a/flake.lock
+++ b/flake.lock
@@ -3,11 +3,11 @@
     "nixpkgs-lib": {
       "locked": {
         "dir": "lib",
-        "lastModified": 1688049487,
-        "narHash": "sha256-100g4iaKC9MalDjUW9iN6Jl/OocTDtXdeAj7pEGIRh4=",
+        "lastModified": 1690881714,
+        "narHash": "sha256-h/nXluEqdiQHs1oSgkOOWF+j8gcJMWhwnZ9PFabN6q0=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "4bc72cae107788bf3f24f30db2e2f685c9298dc9",
+        "rev": "9e1960bc196baf6881340d53dccb203a951745a2",
         "type": "github"
       },
       "original": {

From 62434060bcbf06591dc9c7dd56f7f35d4ce1d835 Mon Sep 17 00:00:00 2001
From: Hercules CI Effects <hercules-ci[bot]@users.noreply.github.com>
Date: Fri, 1 Sep 2023 23:36:21 +0000
Subject: [PATCH 20/27] flake.lock: Update
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Flake lock file updates:

• Updated input 'nixpkgs-lib':
    'github:NixOS/nixpkgs/9e1960bc196baf6881340d53dccb203a951745a2?dir=lib' (2023-08-01)
  → 'github:NixOS/nixpkgs/3e52e76b70d5508f3cec70b882a29199f4d1ee85?dir=lib' (2023-08-31)
---
 flake.lock | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/flake.lock b/flake.lock
index f31d601..ed348f6 100644
--- a/flake.lock
+++ b/flake.lock
@@ -3,11 +3,11 @@
     "nixpkgs-lib": {
       "locked": {
         "dir": "lib",
-        "lastModified": 1690881714,
-        "narHash": "sha256-h/nXluEqdiQHs1oSgkOOWF+j8gcJMWhwnZ9PFabN6q0=",
+        "lastModified": 1693471703,
+        "narHash": "sha256-0l03ZBL8P1P6z8MaSDS/MvuU8E75rVxe5eE1N6gxeTo=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "9e1960bc196baf6881340d53dccb203a951745a2",
+        "rev": "3e52e76b70d5508f3cec70b882a29199f4d1ee85",
         "type": "github"
       },
       "original": {

From 2d841c9122c5d1f4d33c68e02949379d0aabe15c Mon Sep 17 00:00:00 2001
From: Hercules CI Effects <hercules-ci[bot]@users.noreply.github.com>
Date: Sun, 1 Oct 2023 23:36:24 +0000
Subject: [PATCH 21/27] flake.lock: Update
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Flake lock file updates:

• Updated input 'nixpkgs-lib':
    'github:NixOS/nixpkgs/3e52e76b70d5508f3cec70b882a29199f4d1ee85?dir=lib' (2023-08-31)
  → 'github:NixOS/nixpkgs/f5892ddac112a1e9b3612c39af1b72987ee5783a?dir=lib' (2023-09-29)
---
 flake.lock | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/flake.lock b/flake.lock
index ed348f6..86218ee 100644
--- a/flake.lock
+++ b/flake.lock
@@ -3,11 +3,11 @@
     "nixpkgs-lib": {
       "locked": {
         "dir": "lib",
-        "lastModified": 1693471703,
-        "narHash": "sha256-0l03ZBL8P1P6z8MaSDS/MvuU8E75rVxe5eE1N6gxeTo=",
+        "lastModified": 1696019113,
+        "narHash": "sha256-X3+DKYWJm93DRSdC5M6K5hLqzSya9BjibtBsuARoPco=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "3e52e76b70d5508f3cec70b882a29199f4d1ee85",
+        "rev": "f5892ddac112a1e9b3612c39af1b72987ee5783a",
         "type": "github"
       },
       "original": {

From 6c88b316212611e0864c8f0e79fe40086af40afb Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Tue, 3 Oct 2023 16:05:44 +0200
Subject: [PATCH 22/27] Add template/package

---
 template/package/flake.nix         | 21 +++++++++++++++++++++
 template/package/hello/hello.sh    |  3 +++
 template/package/hello/package.nix | 22 ++++++++++++++++++++++
 template/package/hello/test.nix    | 12 ++++++++++++
 4 files changed, 58 insertions(+)
 create mode 100644 template/package/flake.nix
 create mode 100644 template/package/hello/hello.sh
 create mode 100644 template/package/hello/package.nix
 create mode 100644 template/package/hello/test.nix

diff --git a/template/package/flake.nix b/template/package/flake.nix
new file mode 100644
index 0000000..385e6cb
--- /dev/null
+++ b/template/package/flake.nix
@@ -0,0 +1,21 @@
+{
+  description = "Description for the project";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+  };
+
+  outputs = inputs@{ flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      systems = [ "x86_64-linux" "aarch64-linux" "aarch64-darwin" "x86_64-darwin" ];
+      perSystem = { config, pkgs, ... }: {
+        packages.default = config.packages.hello;
+
+        packages.hello = pkgs.callPackage ./hello/package.nix { };
+
+        checks.hello = pkgs.callPackage ./hello/test.nix {
+          hello = config.packages.hello;
+        };
+      };
+    };
+}
diff --git a/template/package/hello/hello.sh b/template/package/hello/hello.sh
new file mode 100644
index 0000000..30a4bc0
--- /dev/null
+++ b/template/package/hello/hello.sh
@@ -0,0 +1,3 @@
+#!@shell@
+
+echo Hello world
diff --git a/template/package/hello/package.nix b/template/package/hello/package.nix
new file mode 100644
index 0000000..cfc64bc
--- /dev/null
+++ b/template/package/hello/package.nix
@@ -0,0 +1,22 @@
+{ stdenv, lib, runtimeShell }:
+
+# Example package in the style that `mkDerivation`-based packages in Nixpkgs are written.
+stdenv.mkDerivation (finalAttrs: {
+  name = "hello";
+  src = lib.cleanSourceWith {
+    src = ./.;
+    filter = path: type:
+      type == "regular" -> baseNameOf path == "hello.sh";
+  };
+  buildPhase = ''
+    # Note that Nixpkgs has builder functions for simple packages
+    # like this, but this template avoids it to make for a more
+    # complete example.
+    substitute hello.sh hello --replace '@shell@' ${runtimeShell}
+    cat hello
+    chmod a+x hello
+  '';
+  installPhase = ''
+    install -D hello $out/bin/hello
+  '';
+})
diff --git a/template/package/hello/test.nix b/template/package/hello/test.nix
new file mode 100644
index 0000000..424e4a8
--- /dev/null
+++ b/template/package/hello/test.nix
@@ -0,0 +1,12 @@
+{ hello, runCommand }:
+
+runCommand "test-hello"
+{
+  inherit hello;
+} '' 
+  (
+    set -x
+    [[ "Hello world" == "$(${hello}/bin/hello)" ]]
+  )
+  touch $out
+''

From 9551c1dbc170193d2cf59b3bc6648a59b536ad7d Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Sun, 1 Oct 2023 13:34:27 +0100
Subject: [PATCH 23/27] transposition: Improve doc

---
 modules/transposition.nix | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/modules/transposition.nix b/modules/transposition.nix
index a89b9c8..7e985ba 100644
--- a/modules/transposition.nix
+++ b/modules/transposition.nix
@@ -31,6 +31,13 @@ in
       description = ''
         A helper that defines transposed attributes in the flake outputs.
 
+        When you define `transposition.foo = { };`, definitions are added to the effect of (pseudo-code):
+
+        ```nix
+        flake.foo.''${system} = (perSystem system).foo;
+        perInput = system: inputFlake: inputFlake.foo.''${system};
+        ```
+
         Transposition is the operation that swaps the indices of a data structure.
         Here it refers specifically to the transposition between
 

From fc74939824cc92da3a39a6eb37ae2b7df89f55c3 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Fri, 13 Oct 2023 23:02:24 +0200
Subject: [PATCH 24/27] mkFlake: Prefer unsafeGetAttrPos over self.outPath for
 error message

This would not be advisable for anything other than error messages,
because Nix does not commit to any semantics for that function.
---
 lib.nix | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/lib.nix b/lib.nix
index 33f20e4..f338367 100644
--- a/lib.nix
+++ b/lib.nix
@@ -121,14 +121,17 @@ let
 
     mkFlake = args: module:
       let
-        loc =
+        inputsPos = builtins.unsafeGetAttrPos "inputs" args;
+        moduleLocation =
           args.moduleLocation or (
-            if args?inputs.self.outPath
+            if inputsPos != null
+            then inputsPos.file
+            else if args?inputs.self.outPath
             then args.inputs.self.outPath + "/flake.nix"
             else "<mkFlake argument>"
           );
-        mod = lib.setDefaultModuleLocation loc module;
-        eval = flake-parts-lib.evalFlakeModule args mod;
+        mod = lib.setDefaultModuleLocation moduleLocation module;
+        eval = flake-parts-lib.evalFlakeModule (args // { inherit moduleLocation; }) mod;
       in
       eval.config.flake;
 

From f427ecf1a05493c788a94ee3b70bccd7285a64b5 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Fri, 13 Oct 2023 23:49:17 +0200
Subject: [PATCH 25/27] Repurpose moduleLocation impl for new errorLocation

The difference is that moduleLocation is "guaranteed" reliable data,
whereas errorLocation is the best choice for error messages in the core.

moduleLocation is suitable for the module key attribute.
errorLocation is best for the *ROOT* module _file attribute.

Initially I applied errorLocation in too many places. It is only needed
when the flake output attribute names are strict in it.
To avoid confusion, I'm not exposing errorLocation to the modules, until
we have a concrete use case for it.
---
 dev/tests/eval-tests.nix | 22 ++++++++++++++++++++++
 lib.nix                  | 28 +++++++++++++++++-----------
 2 files changed, 39 insertions(+), 11 deletions(-)

diff --git a/dev/tests/eval-tests.nix b/dev/tests/eval-tests.nix
index 437ee1a..c3c03b6 100644
--- a/dev/tests/eval-tests.nix
+++ b/dev/tests/eval-tests.nix
@@ -26,6 +26,22 @@ rec {
       systems = [ ];
     };
 
+  emptyExposeArgs = mkFlake
+    { inputs.self = { outPath = "the self outpath"; }; }
+    ({ config, moduleLocation, errorLocation, ... }: {
+      flake = {
+        inherit moduleLocation errorLocation;
+      };
+    });
+
+  emptyExposeArgsNoSelf = mkFlake
+    { inputs.self = throw "self won't be available in case of some errors"; }
+    ({ config, moduleLocation, errorLocation, ... }: {
+      flake = {
+        inherit moduleLocation errorLocation;
+      };
+    });
+
   example1 = mkFlake
     { inputs.self = { }; }
     {
@@ -162,6 +178,12 @@ rec {
 
     assert packagesNonStrictInDevShells.packages.a.default == pkg "a" "hello";
 
+    assert emptyExposeArgs.moduleLocation == "the self outpath/flake.nix";
+
+    assert emptyExposeArgs.errorLocation == __curPos.file;
+
+    assert emptyExposeArgsNoSelf.errorLocation == __curPos.file;
+
     ok;
 
   result = runTests "ok";
diff --git a/lib.nix b/lib.nix
index f338367..eaa5679 100644
--- a/lib.nix
+++ b/lib.nix
@@ -83,6 +83,22 @@ let
         '')
       , moduleLocation ? "${self.outPath}/flake.nix"
       }:
+      let
+        module = lib.setDefaultModuleLocation errorLocation module;
+        inputsPos = builtins.unsafeGetAttrPos "inputs" args;
+        errorLocation =
+          # Best case: user makes it explicit
+          args.moduleLocation or (
+            # Slightly worse: Nix does not technically commit to unsafeGetAttrPos semantics
+            if inputsPos != null
+            then inputsPos.file
+            # Slightly worse: self may not be valid when an error occurs
+            else if args?inputs.self.outPath
+            then args.inputs.self.outPath + "/flake.nix"
+            # Fallback
+            else "<mkFlake argument>"
+          );
+      in
       throwIf
         (!args?self && !args?inputs) ''
         When invoking flake-parts, you must pass in the flake output arguments.
@@ -121,17 +137,7 @@ let
 
     mkFlake = args: module:
       let
-        inputsPos = builtins.unsafeGetAttrPos "inputs" args;
-        moduleLocation =
-          args.moduleLocation or (
-            if inputsPos != null
-            then inputsPos.file
-            else if args?inputs.self.outPath
-            then args.inputs.self.outPath + "/flake.nix"
-            else "<mkFlake argument>"
-          );
-        mod = lib.setDefaultModuleLocation moduleLocation module;
-        eval = flake-parts-lib.evalFlakeModule (args // { inherit moduleLocation; }) mod;
+        eval = flake-parts-lib.evalFlakeModule args module;
       in
       eval.config.flake;
 

From c8c8e5661e2b93f2459b0ed6da1cbe31c7dba347 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Sat, 14 Oct 2023 00:06:42 +0200
Subject: [PATCH 26/27] Remove errorLocation from the tests

As mentioned in the previous commit, we don't have a use case for
this in flake-parts yet, as far as I'm aware. It can be exposed
when we do have a concrete use case where it is needed.
---
 dev/tests/eval-tests.nix | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/dev/tests/eval-tests.nix b/dev/tests/eval-tests.nix
index c3c03b6..2da3d99 100644
--- a/dev/tests/eval-tests.nix
+++ b/dev/tests/eval-tests.nix
@@ -28,17 +28,17 @@ rec {
 
   emptyExposeArgs = mkFlake
     { inputs.self = { outPath = "the self outpath"; }; }
-    ({ config, moduleLocation, errorLocation, ... }: {
+    ({ config, moduleLocation, ... }: {
       flake = {
-        inherit moduleLocation errorLocation;
+        inherit moduleLocation;
       };
     });
 
   emptyExposeArgsNoSelf = mkFlake
     { inputs.self = throw "self won't be available in case of some errors"; }
-    ({ config, moduleLocation, errorLocation, ... }: {
+    ({ config, moduleLocation, ... }: {
       flake = {
-        inherit moduleLocation errorLocation;
+        inherit moduleLocation;
       };
     });
 
@@ -180,10 +180,6 @@ rec {
 
     assert emptyExposeArgs.moduleLocation == "the self outpath/flake.nix";
 
-    assert emptyExposeArgs.errorLocation == __curPos.file;
-
-    assert emptyExposeArgsNoSelf.errorLocation == __curPos.file;
-
     ok;
 
   result = runTests "ok";

From e21f594423a34944b2eece27e62f1fcca0c1c90a Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Sun, 29 Oct 2023 12:30:12 +0100
Subject: [PATCH 27/27] Fix error location

The path didn't make it into the message because of a silly coding
mistake and overlooking the actual location in manual testing.
---
 lib.nix | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib.nix b/lib.nix
index eaa5679..64c35c1 100644
--- a/lib.nix
+++ b/lib.nix
@@ -84,7 +84,6 @@ let
       , moduleLocation ? "${self.outPath}/flake.nix"
       }:
       let
-        module = lib.setDefaultModuleLocation errorLocation module;
         inputsPos = builtins.unsafeGetAttrPos "inputs" args;
         errorLocation =
           # Best case: user makes it explicit
@@ -120,7 +119,7 @@ let
             inherit self flake-parts-lib moduleLocation;
             inputs = args.inputs or /* legacy, warned above */ self.inputs;
           } // specialArgs;
-          modules = [ ./all-modules.nix module ];
+          modules = [ ./all-modules.nix (lib.setDefaultModuleLocation errorLocation module) ];
         }
         );