scons_3_1_2: detach from sconsPackages

pkgs/development/tools/build-managers/scons/3.1.2.nix

@@ -0,0 +1,38 @@
+{ lib, fetchurl, python3 }:
+
+let
+  pname = "scons";
+  version = "3.1.2";
+  src = fetchurl {
+    url = "mirror://sourceforge/scons/scons-${version}.tar.gz";
+    hash = "sha256-eAHz9i9lRSjict94C+EMDpM36JdlC2Ldzunzn94T+Ps=";
+  };
+in
+python3.pkgs.buildPythonApplication {
+  inherit pname version src;
+
+  setupHook = ./setup-hook.sh;
+
+  doCheck = true;
+
+  passthru = {
+    # expose the used python version so tools using this (and extensing scos
+    # with other python modules) can use the exact same python version.
+    inherit python3;
+    python = python3;
+  };
+
+  meta = {
+    description = "An improved, cross-platform substitute for Make";
+    longDescription = ''
+      SCons is an Open Source software construction tool. Think of SCons as an
+      improved, cross-platform substitute for the classic Make utility with
+      integrated functionality similar to autoconf/automake and compiler caches
+      such as ccache. In short, SCons is an easier, more reliable and faster way
+      to build software.
+    '';
+    homepage = "https://scons.org/";
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ AndersonTorres ];
+  };
+}

pkgs/development/tools/build-managers/scons/default.nix

@@ -5,10 +5,6 @@ let
     python = python3;
   };
 in {
-  scons_3_1_2 = (mkScons {
-    version = "3.1.2";
-    sha256 = "1yzq2gg9zwz9rvfn42v5jzl3g4qf1khhny6zfbi2hib55zvg60bq";
-  });
   scons_4_1_0 = mkScons {
     version = "4.1.0";
     sha256 = "11axk03142ziax6i3wwy9qpqp7r3i7h5jg9y2xzph9i15rv8vlkj";

pkgs/top-level/all-packages.nix

@@ -20064,6 +20064,8 @@ with pkgs;
 
   sca2d = callPackage ../development/tools/sca2d {  };
 
+  scons_3_1_2 = callPackage ../development/tools/build-managers/scons/3.1.2.nix { };
+
   sconsPackages = dontRecurseIntoAttrs (callPackage ../development/tools/build-managers/scons { });
   scons = sconsPackages.scons_latest;