better error message when git config fails to parse remote config

Rather than leaking the name of the temp file, just say the config parse
failed, and where the config was downloaded from.

Not closing the bug report because two issues were reported in the same
bug report, because the universe wants me to continually re-read old
unclosed bug reports to waste my time determining what still needs to be
done.

Git/Config.hs

@@ -1,6 +1,6 @@
 {- git repository configuration handling
  -
- - Copyright 2010-2019 Joey Hess <id@joeyh.name>
+ - Copyright 2010-2020 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -14,6 +14,7 @@ import qualified Data.ByteString as S
 import qualified Data.ByteString.Char8 as S8
 import Data.Char
 import qualified System.FilePath.ByteString as P
+import Control.Concurrent.Async
 
 import Common
 import Git
@@ -184,19 +185,22 @@ coreBare = "core.bare"
 
 {- Runs a command to get the configuration of a repo,
  - and returns a repo populated with the configuration, as well as the raw
- - output of the command. -}
-fromPipe :: Repo -> String -> [CommandParam] -> IO (Either SomeException (Repo, S.ByteString))
+ - output and any standard output of the command. -}
+fromPipe :: Repo -> String -> [CommandParam] -> IO (Either SomeException (Repo, S.ByteString, S.ByteString))
 fromPipe r cmd params = try $
-	withHandle StdoutHandle createProcessSuccess p $ \h -> do
-		val <- S.hGetContents h
+	withOEHandles createProcessSuccess p $ \(hout, herr) -> do
+		geterr <- async $ S.hGetContents herr
+		getval <- async $ S.hGetContents hout
+		val <- wait getval
+		err <- wait geterr
 		r' <- store val r
-		return (r', val)
+		return (r', val, err)
   where
 	p = proc cmd $ toCommand params
 
 {- Reads git config from a specified file and returns the repo populated
  - with the configuration. -}
-fromFile :: Repo -> FilePath -> IO (Either SomeException (Repo, S.ByteString))
+fromFile :: Repo -> FilePath -> IO (Either SomeException (Repo, S.ByteString, S.ByteString))
 fromFile r f = fromPipe r "git"
 	[ Param "config"
 	, Param "--file"

Remote/GCrypt.hs

@@ -56,6 +56,7 @@ import Utility.Tmp
 import Logs.Remote
 import Utility.Gpg
 import Utility.SshHost
+import Utility.Tuple
 import Messages.Progress
 import Types.ProposedAccepted
 
@@ -471,7 +472,7 @@ getGCryptId :: Bool -> Git.Repo -> RemoteGitConfig -> Annex (Maybe Git.GCrypt.GC
 getGCryptId fast r gc
 	| Git.repoIsLocal r || Git.repoIsLocalUnknown r = extract <$>
 		liftIO (catchMaybeIO $ Git.Config.read r)
-	| not fast = extract . liftM fst <$> getM (eitherToMaybe <$>)
+	| not fast = extract . liftM fst3 <$> getM (eitherToMaybe <$>)
 		[ Ssh.onRemote NoConsumeStdin r (\f p -> liftIO (Git.Config.fromPipe r f p), return (Left $ error "configlist failed")) "configlist" [] []
 		, getConfigViaRsync r gc
 		]
@@ -480,7 +481,7 @@ getGCryptId fast r gc
 	extract Nothing = (Nothing, r)
 	extract (Just r') = (fromConfigValue <$> Git.Config.getMaybe coreGCryptId r', r')
 
-getConfigViaRsync :: Git.Repo -> RemoteGitConfig -> Annex (Either SomeException (Git.Repo, S.ByteString))
+getConfigViaRsync :: Git.Repo -> RemoteGitConfig -> Annex (Either SomeException (Git.Repo, S.ByteString, S.ByteString))
 getConfigViaRsync r gc = do
 	(rsynctransport, rsyncurl, _) <- rsyncTransport r gc
 	opts <- rsynctransport

Remote/Git.hs

@@ -248,7 +248,7 @@ tryGitConfigRead autoinit r
 	| haveconfig r = return r -- already read
 	| Git.repoIsSsh r = storeUpdatedRemote $ do
 		v <- Ssh.onRemote NoConsumeStdin r
-			(pipedconfig autoinit, return (Left $ giveup "configlist failed"))
+			(pipedconfig autoinit (Git.repoDescribe r), return (Left $ giveup "configlist failed"))
 			"configlist" [] configlistfields
 		case v of
 			Right r'
@@ -263,23 +263,25 @@ tryGitConfigRead autoinit r
   where
 	haveconfig = not . M.null . Git.config
 
-	pipedconfig mustincludeuuuid cmd params = do
+	pipedconfig mustincludeuuuid configloc cmd params = do
 		v <- liftIO $ Git.Config.fromPipe r cmd params
 		case v of
-			Right (r', val) -> do
+			Right (r', val, _err) -> do
 				unless (isUUIDConfigured r' || S.null val || not mustincludeuuuid) $ do
 					warning $ "Failed to get annex.uuid configuration of repository " ++ Git.repoDescribe r
 					warning $ "Instead, got: " ++ show val
 					warning $ "This is unexpected; please check the network transport!"
 				return $ Right r'
-			Left l -> return $ Left l
+			Left l -> do
+				warning $ "Unable to parse git config from " ++ configloc
+				return $ Left l
 
 	geturlconfig = Url.withUrlOptions $ \uo -> do
 		v <- withTmpFile "git-annex.tmp" $ \tmpfile h -> do
 			liftIO $ hClose h
 			let url = Git.repoLocation r ++ "/config"
 			ifM (liftIO $ Url.downloadQuiet nullMeterUpdate url tmpfile uo)
-				( Just <$> pipedconfig False "git" [Param "config", Param "--null", Param "--list", Param "--file", File tmpfile]
+				( Just <$> pipedconfig False url "git" [Param "config", Param "--null", Param "--list", Param "--file", File tmpfile]
 				, return Nothing
 				)
 		case v of

doc/bugs/leaks_git_config_error_message_upon_inability_to_read_downloaded___34__config__34___file.mdwn

@@ -1,3 +1,5 @@
+[[!meta title="http remotes that require authentication are not yet supported"]]
+
 It is not a ground shaking issue, but probably would be best to handle it more gracefully.
 
 Initially mentioned while doing install using datalad. Account/permission is required to access this particular repo, ask Canadians for access if you don't have it yet Joey.  credentials I guess got asked for and cached by git upon initial invocation, so upon subsequent calls didn't ask for any:

doc/bugs/leaks_git_config_error_message_upon_inability_to_read_downloaded___34__config__34___file/comment_5_495820d777c889f88466d725c11895f9._comment

@@ -0,0 +1,7 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 5"""
+ date="2020-01-22T17:04:09Z"
+ content="""
+Error message has been improved.
+"""]]