openbugs: switch to new upstream (#316714)

pkgs/applications/science/machine-learning/openbugs/default.nix

@@ -1,22 +1,27 @@
 { lib
 , stdenv
-, fetchurl
+, fetchFromGitHub
 }:
 
 stdenv.mkDerivation rec {
   pname = "OpenBUGS";
   version = "3.2.3";
 
-  src = fetchurl {
-    url = "https://www.mrc-bsu.cam.ac.uk/wp-content/uploads/2018/04/${pname}-${version}.tar.gz";
-    sha256 = "sha256-oonE2gxKw3H4ATImyF69Cp4d7F3puFiVDkhUy4FLTtg=";
+  outputs = [ "out" ];
+
+  src = fetchFromGitHub {
+    owner = "jsta";
+    repo = "openbugs";
+    rev = "cd921342ba13ee89ee60f9aebd2e96c42bd59ae3";
+    sha256 = "sha256-11LrScN1kvtq0Fo7RWGjbQO0U5b5brCbipl5pdZnrFs=";
   };
 
   meta = with lib; {
-    description = "Open source program for Bayesian modelling based on MCMC";
+    description = "Software package for performing Bayesian analysis and simulation using Markov Chain Monte Carlo";
     homepage = "https://www.mrc-bsu.cam.ac.uk/software/bugs/openbugs/";
-    maintainers = with maintainers; [ andresnav ];
+    changelog = "https://github.com/jsta/openbugs/blob/master/ChangeLog";
+    platforms = [ "i686-linux" "x86_64-linux" ];
     license = licenses.gpl3Only;
-    platforms = [ "i686-linux" ];
+    maintainers = with maintainers; [ andresnav ];
   };
 }