add build flags to version output

BuildFlags.hs

@@ -0,0 +1,51 @@
+{- git-annex build flags reporting
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module BuildFlags where
+
+buildFlags :: [String]
+buildFlags = filter (not . null)
+	[ ""
+#ifdef WITH_ASSISTANT
+	, "Assistant"
+#endif
+#ifdef WITH_WEBAPP
+	, "Webapp"
+#endif
+#ifdef WITH_PAIRING
+	, "Pairing"
+#endif
+#ifdef WITH_TESTSUITE
+	, "Testsuite"
+#endif
+#ifdef WITH_S3
+	, "S3"
+#endif
+#ifdef WITH_WEBDAV
+	, "WebDAV"
+#endif
+#ifdef WITH_INOTIFY
+	, "Inotify"
+#endif
+#ifdef WITH_FSEVENTS
+	, "FsEvents"
+#endif
+#ifdef WITH_KQUEUE
+	, "Kqueue"
+#endif
+#ifdef WITH_DBUS
+	, "DBus"
+#endif
+#ifdef WITH_XMPP
+	, "XMPP"
+#endif
+#ifdef WITH_DNS
+	, "DNS"
+#endif
+	]

Command/Version.hs

@@ -11,6 +11,7 @@ import Common.Annex
 import Command
 import qualified Build.SysConfig as SysConfig
 import Annex.Version
+import BuildFlags
 
 def :: [Command]
 def = [noCommit $ noRepo showPackageVersion $ dontCheck repoExists $
@@ -28,6 +29,7 @@ start = do
 		putStrLn $ "default repository version: " ++ defaultVersion
 		putStrLn $ "supported repository versions: " ++ vs supportedVersions
 		putStrLn $ "upgrade supported from repository versions: " ++ vs upgradableVersions
+		putStrLn $ "build flags: " ++ unwords buildFlags
 	stop
   where
 	vs = join " "