mpfr: 4.1.0 -> 4.1.1

Changes: https://www.mpfr.org/mpfr-4.1.0/#fixed

While at it added trivial updater script.

pkgs/development/libraries/mpfr/default.nix

@@ -1,4 +1,9 @@
-{ lib, stdenv, fetchurl, gmp }:
+{ lib
+, stdenv
+, fetchurl
+, gmp
+, writeScript
+}:
 
 # Note: this package is used for bootstrapping fetchurl, and thus
 # cannot use fetchpatch! All mutable patches (generated by GitHub or
@@ -6,15 +11,15 @@
 # files.
 
 stdenv.mkDerivation rec {
-  version = "4.1.0";
+  version = "4.1.1";
   pname = "mpfr";
 
   src = fetchurl {
     urls = [
-      #"https://www.mpfr.org/${name}/${name}.tar.xz"
+      "https://www.mpfr.org/${pname}-${version}/${pname}-${version}.tar.xz"
       "mirror://gnu/mpfr/${pname}-${version}.tar.xz"
     ];
-    sha256 = "0zwaanakrqjf84lfr5hfsdr7hncwv9wj0mchlr7cmxigfgqs760c";
+    hash = "sha256-/9GVvVZ9uv/DuYsj/QCq0FN2gMmJYXHkT+P/eeKKwz0=";
   };
 
   outputs = [ "out" "dev" "doc" "info" ];
@@ -31,6 +36,20 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
+  passthru = {
+    updateScript = writeScript "update-mpfr" ''
+      #!/usr/bin/env nix-shell
+      #!nix-shell -i bash -p curl pcre common-updater-scripts
+
+      set -eu -o pipefail
+
+      # Expect the text in format of '<title>GNU MPFR version 4.1.1</title>'
+      new_version="$(curl -s https://www.mpfr.org/mpfr-current/ |
+          pcregrep -o1 '<title>GNU MPFR version ([0-9.]+)</title>')"
+      update-source-version ${pname} "$new_version"
+    '';
+  };
+
   meta = {
     homepage = "https://www.mpfr.org/";
     description = "Library for multiple-precision floating-point arithmetic";