xapianBindings: 1.2.23 -> 1.4.0

The xapianBindings version is now directly tied to the input xapian
version, to ensure that they're in synch.

Also, as of this version, sphinx is required to build documentation
for the python bindings.

pkgs/development/libraries/xapian/bindings/default.nix

@@ -1,15 +1,18 @@
 { stdenv, composableDerivation, fetchurl, xapian, pkgconfig, zlib
-, python ? null, php ? null, ruby ? null }:
+, python ? null, sphinx ? null, php ? null, ruby ? null }:
+
+assert (python != null) -> (sphinx != null);
 
 let inherit (composableDerivation) wwf; in
 
 composableDerivation.composableDerivation {} rec {
 
-  name = "xapian-bindings-1.2.23";
+  name = "xapian-bindings-${version}";
+  version = (builtins.parseDrvName xapian.name).version;
 
   src = fetchurl {
-    url = "http://oligarchy.co.uk/xapian/1.2.23/${name}.tar.xz";
-    sha256 = "05929d9bq9df25kh2i6gk2w09w7p5qknf9cc7mrm2g46finbbd0r";
+    url = "http://oligarchy.co.uk/xapian/${version}/${name}.tar.xz";
+    sha256 = "0lv2zblayfax4v7z3sj067b0av0phf3gc2s2d1cvkw0bkl07mv1s";
   };
 
   buildInputs = [ xapian pkgconfig zlib ];
@@ -19,7 +22,7 @@ composableDerivation.composableDerivation {} rec {
          wwf {
            name = "python";
            enable = {
-            buildInputs = [ python ];
+            buildInputs = [ python sphinx ];
             # export same env vars as in pythonNew
             preConfigure = ''
               export PYTHON_LIB=$out/lib/${python.libPrefix}/site-packages

pkgs/top-level/all-packages.nix

@@ -9800,6 +9800,7 @@ in
 
   xapianBindings = callPackage ../development/libraries/xapian/bindings {  # TODO perl php Java, tcl, C#, python
     php = php56;
+    sphinx = pythonPackages.sphinx;
   };
 
   xapian-omega = callPackage ../tools/misc/xapian-omega {