plr: init at REL8_4_1

Co-authored-by: Sandro <sandro.jaeckel@gmail.com>

pkgs/servers/sql/postgresql/ext/plr.nix

@@ -0,0 +1,31 @@
+{ lib, stdenv, fetchFromGitHub, pkg-config, R, postgresql }:
+
+stdenv.mkDerivation rec {
+  pname = "plr";
+  version = "8.4.1";
+
+  src = fetchFromGitHub {
+    owner = "postgres-plr";
+    repo = "plr";
+    rev = "REL${builtins.replaceStrings ["."] ["_"] version}";
+    sha256 = "1wy4blg8jl30kzhrkvbncl4gmy6k71zipnq89ykwi1vmx89v3ab7";
+  };
+
+  nativeBuildInputs = [ pkg-config ];
+  buildInputs = [ R postgresql ];
+  preBuild = ''
+    export USE_PGXS=1
+  '';
+  installPhase = ''
+    install -D plr.so -t $out/lib/
+    install -D {plr--unpackaged--8.4.1.sql,plr--8.4.1.sql,plr.control} -t $out/share/postgresql/extension
+  '';
+
+  meta = with lib; {
+    description = "PL/R - R Procedural Language for PostgreSQL";
+    homepage = "https://github.com/postgres-plr/plr";
+    maintainers = with maintainers; [ qoelet ];
+    platforms = [ "x86_64-linux" ];
+    license = licenses.gpl2Only;
+  };
+}