isync: Add unstable variant.

pkgs/tools/networking/isync/unstable.nix

@@ -0,0 +1,29 @@
+{ fetchgit, stdenv, openssl, pkgconfig, db, cyrus_sasl
+, autoconf, automake }:
+
+stdenv.mkDerivation rec {
+  name = "isync-git-2015-11-08";
+  rev = "46e792";
+
+  src = fetchgit {
+    url = "git://git.code.sf.net/p/isync/isync";
+    inherit rev;
+    sha256 = "1flm9lkgf1pa6aa678xr0yj5fxwh8c9jpjzd4002f4jjmcf4w57s";
+  };
+
+  buildInputs = [ openssl pkgconfig db cyrus_sasl autoconf automake ];
+
+  preConfigure = ''
+    touch ChangeLog
+    ./autogen.sh
+  '';
+
+  meta = with stdenv.lib; {
+    homepage = http://isync.sourceforge.net/;
+    description = "Free IMAP and MailDir mailbox synchronizer";
+    license = licenses.gpl2Plus;
+
+    maintainers = with maintainers; [ the-kenny ];
+    platforms = platforms.unix;
+  };
+}

pkgs/top-level/all-packages.nix

@@ -1977,6 +1977,7 @@ let
   isl_0_15 = callPackage ../development/libraries/isl/0.15.0.nix { };
 
   isync = callPackage ../tools/networking/isync { };
+  isyncUnstable = callPackage ../tools/networking/isync/unstable.nix { };
 
   jaaa = callPackage ../applications/audio/jaaa { };