Problem: support multiple direnv environment (#1352)

.envrc.example

@@ -0,0 +1,5 @@
+# default: go, gomod2nix
+# rocksdb: go, gomod2nix, librocksdb
+# full:    go, gomod2nix, librocksdb, python env
+use flake .#full
+TMPDIR=/tmp

.gitignore

@@ -21,3 +21,7 @@ go.work.sum
 
 # yaml for test
 integration_tests/configs/*.yaml
+
+# direnv
+/.envrc
+/.direnv

flake.nix

@@ -11,9 +11,14 @@
       inputs.nixpkgs.follows = "nixpkgs";
       inputs.flake-utils.follows = "flake-utils";
     };
+    poetry2nix = {
+      url = "github:nix-community/poetry2nix";
+      inputs.nixpkgs.follows = "nixpkgs";
+      inputs.flake-utils.follows = "flake-utils";
+    };
   };
 
-  outputs = { self, nixpkgs, nix-bundle-exe, gomod2nix, flake-utils }:
+  outputs = { self, nixpkgs, nix-bundle-exe, gomod2nix, flake-utils, poetry2nix }:
     let
       rev = self.shortRev or "dirty";
       mkApp = drv: {
@@ -28,6 +33,7 @@
             inherit system;
             overlays = [
               (import ./nix/build_overlay.nix)
+              poetry2nix.overlays.default
               gomod2nix.overlays.default
               self.overlay
             ];
@@ -58,13 +64,22 @@
                 pkgs.rocksdb
               ];
             };
+            full = pkgs.mkShell {
+              buildInputs = [
+                defaultPackage.go
+                pkgs.gomod2nix
+                pkgs.rocksdb
+                pkgs.test-env
+              ];
+            };
           };
           legacyPackages = pkgs;
         }
       )
     ) // {
       overlay = final: super: {
         go = super.go_1_22;
+        test-env = final.callPackage ./nix/testenv.nix { };
         bundle-exe = final.pkgsBuildBuild.callPackage nix-bundle-exe { };
         # make-tarball don't follow symbolic links to avoid duplicate file, the bundle should have no external references.
         # reset the ownership and permissions to make the extract result more normal.