Fix build failure when wget is not installed.

Build/Configure.hs

@@ -15,6 +15,7 @@ import Utility.Process
 import Utility.SafeCommand
 import Utility.ExternalSHA
 import Utility.Env
+import Utility.Exception
 import qualified Git.Version
 import Utility.DottedVersion
 
@@ -106,7 +107,8 @@ checkWgetQuietProgress = Config "wgetquietprogress" . BoolConfig
 	<$> getWgetVersion 
 
 getWgetVersion :: IO (Maybe DottedVersion)
-getWgetVersion = extract <$> readProcess "wget" ["--version"]
+getWgetVersion = catchDefaultIO Nothing $
+	extract <$> readProcess "wget" ["--version"]
   where
 	extract s = case lines s of
 		[] -> Nothing

debian/changelog

@@ -9,6 +9,7 @@ git-annex (5.20150114) UNRELEASED; urgency=medium
   * remotedaemon: Fix problem that could prevent ssh connections being
     made after two LOSTNET messages were received in a row (perhaps due to
     two different network interfaces being brought down).
+  * Fix build failure when wget is not installed.
 
  -- Joey Hess <id@joeyh.name>  Tue, 13 Jan 2015 17:03:39 -0400
 

doc/bugs/Build_fails_when_no_wget_avalible.mdwn

@@ -38,3 +38,9 @@ ExitFailure 1
 """]]
 
 -- Carl
+
+> wget is not intended to be a hard build dependency. The Debian package
+> should always be built with wget, so it's a build-dependency there.
+>
+> I've fixed the configure script to not crash in this situation.
+> [[done]]. --[[Joey]]