add shell.nix

jabref/shell.nix

@@ -0,0 +1,27 @@
+# Gradle's toolchain support does not work with IntelliJ, thus we have to use buildFHSUserEnv
+
+# https://discourse.nixos.org/t/how-to-create-a-development-environment-with-intellij-idea-and-openjdk/10153
+{
+  pkgs ? import <nixpkgs> {
+     # https://github.com/NixOS/nixpkgs/issues/166220#issuecomment-1745803058
+     config.allowUnfree = true;
+  }
+}:
+
+let
+  unstable = import (fetchTarball https://github.com/NixOS/nixpkgs/archive/nixos-unstable.tar.gz) { };
+  jdk = unstable.jdk23;
+  gradle = unstable.gradle;
+in
+
+(
+  pkgs.buildFHSUserEnv
+  {
+    name = "intellij-gradle-jdk23";
+    targetPkgs = pkgs_: [
+      pkgs_.jetbrains.idea-ultimate
+      jdk
+      gradle
+    ];
+  }
+).env