git-annex: build on Darwin, and rely on cabal to set flags

Fixes #2519

pkgs/applications/version-management/git-and-tools/git-annex/default.nix

@@ -11,7 +11,7 @@
 , tastyHunit, tastyQuickcheck, tastyRerun, text, time, transformers
 , unixCompat, utf8String, uuid, wai, waiLogger, warp, warpTls
 , which, xmlTypes, yesod, yesodCore, yesodDefault, yesodForm
-, yesodStatic
+, yesodStatic, fsnotify
 }:
 
 cabal.mkDerivation (self: {
@@ -22,9 +22,9 @@ cabal.mkDerivation (self: {
   isExecutable = true;
   buildDepends = [
     aeson async blazeBuilder bloomfilter byteable caseInsensitive
-    clientsession cryptoApi cryptohash dataDefault dataenc DAV dbus
-    dlist dns editDistance exceptions extensibleExceptions fdoNotify
-    feed filepath gnutls hamlet hinotify hS3 hslogger HTTP httpClient
+    clientsession cryptoApi cryptohash dataDefault dataenc DAV
+    dlist dns editDistance exceptions extensibleExceptions
+    feed filepath gnutls hamlet hS3 hslogger HTTP httpClient
     httpConduit httpTypes IfElse json liftedBase MissingH monadControl
     mtl network networkConduit networkInfo networkMulticast
     networkProtocolXmpp optparseApplicative QuickCheck random regexTdfa
@@ -32,19 +32,10 @@ cabal.mkDerivation (self: {
     tastyQuickcheck tastyRerun text time transformers unixCompat
     utf8String uuid wai waiLogger warp warpTls xmlTypes yesod yesodCore
     yesodDefault yesodForm yesodStatic
-  ];
+  ] ++ (if !self.stdenv.isDarwin
+        then [ dbus fdoNotify hinotify ] else [ fsnotify ]);
   buildTools = [ bup curl git gnupg1 lsof openssh perl rsync which ];
-  configureFlags = "-fS3
-                    -fWebDAV
-                    -fInotify
-                    -fDbus
-                    -fAssistant
-                    -fWebapp
-                    -fPairing
-                    -fXMPP
-                    -fDNS
-                    -fProduction
-                    -fTDFA";
+  configureFlags = "-fAssistant -fProduction";
   preConfigure = ''
     export HOME="$NIX_BUILD_TOP/tmp"
     mkdir "$HOME"