split dev into config and overrides, hook in via impure.nix

.envrc

@@ -47,3 +47,9 @@
 	printf "%s\n" "$now" >.direnv/pull-date
 	direnv allow # cheeky
 )
+
+export NIX_PATH_ORIG="${NIX_PATH:-}"
+
+# pkgs/top-level/impure.nix go brrr
+export NIXPKGS_CONFIG="$(realpath config.nix)"
+export NIX_PATH="$NIX_PATH${NIX_PATH:+:}nixpkgs-overlays=$(realpath overlays.nix)"

.gitignore

@@ -1,5 +1,6 @@
 *
 !/justfile
-!/dev.nix
+!/config.nix
+!/overlays.nix
 !/.gitignore
 !/.envrc

config.nix

@@ -0,0 +1,6 @@
+{
+  allowUnfree = true;
+  # allowInsecure = true;
+  # allowBroken = true;
+  checkMeta = true;
+}

justfile

@@ -7,6 +7,11 @@ export invokedir := invocation_directory()
 export epoch := `date +%s`
 export GUM_FILTER_HEIGHT := "15"
 export GIT := `command -v git-wait >/dev/null && echo "git-wait" || echo "git"`
+# will trigger a direnv reload when we enter $SHELL
+export DIRENV_WATCHES := ""
+# please no surprises for now
+export NIXPKGS_CONFIG := ""
+export NIX_PATH := `echo "${NIX_PATH_ORIG:-"${NIX_PATH:-}"}"`
 
 # required programs: git nix nom gum fzf tee nix-update
 
@@ -730,27 +735,3 @@ _packages_json:
 @_fmt:
     just --unstable --fmt
     #sd "\n+(@_[a-zA-Z_-]+:)" "\n" justfile
-
-#sync ./dev.nix
-dev:
-    #!/usr/bin/env -S bash -euo pipefail
-    [[ -f "$invokedir"/flake.nix
-    && -f "$invokedir"/default.nix
-    && -e "$invokedir"/.git
-    && -f "$invokedir"/pkgs/top-level/impure.nix
-    ]] || ! echo >&2 "ERROR: not in nixpkgs root"
-
-    # local .gitignore for dev.nix
-    if ! grep -qxF "/dev.nix" master/.git/info/exclude; then
-        echo "/dev.nix" >> master/.git/info/exclude
-    fi
-
-    if [[ ! -f "$invokedir"/dev.nix ]]; then
-        (set -x; cp dev.nix "$invokedir"/dev.nix)
-    elif [[ dev.nix -nt "$invokedir"/dev.nix ]]; then
-        (set -x; cp -f dev.nix "$invokedir"/dev.nix)
-    elif diff -qs dev.nix "$invokedir"/default.nix; then
-        :
-    else
-        ! echo >&2 "dunnolol"
-    fi

overlays.nix

@@ -1,30 +1,9 @@
 #!/usr/bin/env -S nix-instantiate --parse
-{ ... }@cliArgs:
 let
-  lib = import ./lib;
+  lib = import ./master/lib;
   # merge = sets: lib.foldl' lib.recursiveUpdate {} sets;
-  apply = val: f: f val;
   appendIfMissing = list: val: if builtins.elem val list then list else list ++ [ val ];
 
-  mkPkgs =
-    args:
-    import ./. (
-      apply (lib.recursiveUpdate cliArgs args) (prev: rec {
-        # system = ;
-        # crossSystem = ;
-        config.allowUnfree = true;
-        # config.allowInsecure = true;
-        # config.allowBroken = true;
-        config.checkMeta = true;
-        overlays = prev.overlays or [ ] ++ [
-          overlay.withShellCheck
-          overlay.withDebug
-          overlay.withTwostagePythonBuildPassthru
-          # overlay.withPytestCheckHooks
-        ];
-      })
-    );
-
   mkDerivationOverlay =
     let
       # from pkgs/stdenv/adapters.nix
@@ -48,7 +27,9 @@ let
 
       # TODO: need we override any other stdenvs?
       mkStdenvOverlay = f: final: prev: {
-        stdenv = (prev.addAttrsToDerivation { } prev.stdenv).override (f final prev prev.stdenv.mkDerivation);
+        stdenv = (prev.addAttrsToDerivation { } prev.stdenv).override (
+          f final prev prev.stdenv.mkDerivation
+        );
         # stdenvNoCC = (prev.addAttrsToDerivation { } prev.stdenvNoCC).override (f final prev prev.stdenvNoCC.mkDerivation);
         # stdenvLLVM = (prev.addAttrsToDerivation { } prev.stdenvLLVM).override (f final prev prev.stdenvLLVM.mkDerivation);
       };
@@ -67,7 +48,7 @@ let
             let
               stdenv' = stdenv // {
                 # mkDerivation = stdenv.mkDerivationFromStdenv stdenv;
-                mkDerivation = prevMkDerivation;
+                mkDerivation = prevMkDerivation; # HACK
               };
             in
             f final prev stdenv' finalAttrs prevAttrs
@@ -78,16 +59,16 @@ let
 
   # none of these overlays should cause a mass-rebuild, they should only add optional functionality
 
+  # TODO: cccache and sccache
   # TODO: fetchurl.passthru.unpacked
   # TODO: mkDerivation.passthru.withOil: add <package>.withOil which run build with osh, https://oils.pub/osh.html#2-you-get-precise-error-messages
   # TODO: mkDerivation.passthru.withGDB: add <package>.withGDB which runs the full build with gdb
   # TODO: mkDerivation.passthru.withDebInfo: like overlay.withDebug but with cmakeBuildType = "RelWithDebInfo" mode
 
   # usage: nix-build ./dev.nix -A <package>.withDebug
-  overlay.withDebug = mkDerivationOverlay (
+  overlays.withDebug = mkDerivationOverlay (
     final: prev: prevStdenv: finalAttrs: prevAttrs: {
       passthru = {
-        # withDebug = prevStdenv;
         withDebug = prevStdenv.mkDerivation (
           prevAttrs
           // {
@@ -102,7 +83,7 @@ let
   );
 
   # usage: nix-build ./dev.nix -A <package>.shellcheck
-  overlay.withShellCheck = mkDerivationOverlay (
+  overlays.withShellCheck = mkDerivationOverlay (
     final: prev: prevStdenv: finalAttrs: prevAttrs:
     let
       snippets = lib.pipe finalAttrs [
@@ -159,23 +140,24 @@ let
 
   # very hacky, not guaranteed to work, but may save a lot of .whl rebuilds
   # usage: nix-build ./dev.nix -A python3Packages.<package>.twostage
-  overlay.withTwostagePythonBuildPassthru = final: prev: {
+  # usage: nix-build ./dev.nix -A python3Packages.<package>.twostage.first
+  overlays.withTwostagePythonBuildPassthru = final: prev: {
     pythonPackagesExtensions = prev.pythonPackagesExtensions ++ [
       (
         pythonFinal: pythonPrev:
         let
           mkTwostage =
-            builder:
+            buildPythonPackage:
             (
               args:
-              builder (
+              buildPythonPackage (
                 args
                 // {
                   passthru = {
                     twostage =
                       let
                         # TODO: assert "dist" in finalPackage.outputs?
-                        first = builder (
+                        first = buildPythonPackage (
                           args
                           // {
                             name = "${args.name or "${args.pname}-${args.version}"}-wheels";
@@ -210,7 +192,7 @@ let
                             postInstallCheck = null;
                           }
                         );
-                        second = builder (
+                        second = buildPythonPackage (
                           args
                           // {
                             buildPhase = ''
@@ -240,7 +222,7 @@ let
   };
 
   # usage: nativeBuildInputs = [ pytestCheckHookWithGdb ];
-  overlay.withPytestCheckHooks = final: prev: {
+  overlays.withPytestCheckHooks = final: prev: {
     pythonPackagesExtensions = prev.pythonPackagesExtensions ++ [
       (pythonFinal: pythonPrev: {
         pytestCheckHookWithGdb = pythonFinal.pytestCheckHook.override (old: {
@@ -294,19 +276,39 @@ let
     ];
   };
 
+  overlays.toplevelCudaRocmPkgs =
+    final: prev:
+    let
+      mkPkgs =
+        {
+          config ? { },
+          # overlays ? [ ],
+        }:
+        import prev.path {
+          # if we don't specify overlays then impure.nix will do its thing
+          # overlays = prev.overlays + overlays;
+          config = prev.config // config;
+        };
+    in
+    {
+      pkgsCuda = mkPkgs { config.cudaSupport = true; };
+      pkgsRocm = mkPkgs { config.rocmSupport = true; };
+      # pkgsDarwin?
+      # pkgsLinux?
+      # pkgsFreeBSD?
+      # pkgsNetBSD?
+      # pkgsOpenBSD?
+      # pkgsWindows?
+    };
+
 in
-(mkPkgs { })
-// {
-  pkgsCuda = mkPkgs {
-    config.enableCuda = true;
-  };
-  pkgsRocm = mkPkgs {
-    config.enableRocm = true;
-  };
-  # pkgsDarwin
-  # pkgsLinux
-  # pkgsFreeBSD
-  # pkgsNetBSD
-  # pkgsOpenBSD
-  # pkgsWindows
-}
+[
+  overlays.withShellCheck
+  overlays.withDebug
+  overlays.withInvalidateFetcherByDrvHash
+  overlays.withTwostagePythonBuildPassthru
+  overlays.withPytestCheckHooks
+  overlays.toplevelCudaRocmPkgs
+  # WIP:
+  # overlays.withCudaOrRocm
+]