groff, opensp: make deterministic

pkgs/tools/text/groff/default.nix

@@ -28,6 +28,14 @@ stdenv.mkDerivation rec {
     '';
   };
 
+  postInstall = ''
+      # Remove example output with (random?) colors to 
+      # avoid non-determinism in the output
+      rm $out/share/doc/${name}/examples/hdtbl/*color*ps
+      # Remove creation date
+      find $out/share/doc/${name} -type f -print0 | xargs -0 sed -i -e 's/%%CreationDate: .*//'
+    '';
+
   meta = {
     homepage = "http://www.gnu.org/software/groff/";
     description = "GNU Troff, a typesetting package that reads plain text and produces formatted output";

pkgs/tools/text/sgml/opensp/default.nix

@@ -13,8 +13,16 @@ stdenv.mkDerivation {
       docsrc/*.xml
   '';
 
+
   setupHook = ./setup-hook.sh;
 
+  postFixup = ''
+    # Remove random ids in the release notes
+    sed -i -e 's/href="#idm.*"//g' $out/share/doc/OpenSP/releasenotes.html
+    sed -i -e 's/name="idm.*"//g' $out/share/doc/OpenSP/releasenotes.html
+    '';
+
+
   buildInputs = [ xmlto docbook_xml_dtd_412 libxslt docbook_xsl ];
 
   meta = {