suggest when user may want annex.stalldetection

When annex.stalldetection is not enabled, and a likely stall is detected,
display a suggestion to enable it.

Note that the progress meter display is not taken down when displaying
the message, so it will display like this:

	0%    8 B                 0 B/s
	  Transfer seems to have stalled. To handle stalling transfers, configure annex.stalldetection
	0%    10 B                0 B/s

Although of course if it's really stalled, it will never update
again after the message. Taking down the progress meter and starting
a new one doesn't seem too necessary given how unusual this is,
also this does help show the state it was at when it stalled.

Use of uninterruptibleCancel here is ok, the thread it's canceling
only does STM transactions and sleeps. The annex thread that gets
forked off is separate to avoid it being canceled, so that it
can be joined back at the end.

A module cycle required moving from dupState the precaching of the
remote list. Doing it at startConcurrency should cover all the cases
where the remote list is used in concurrent actions.

This commit was sponsored by Kevin Mueller on Patreon.

Command/AddUrl.hs

@@ -332,7 +332,7 @@ downloadWeb addunlockedmatcher o url urlinfo file =
 			let cleanuptmp = pruneTmpWorkDirBefore tmp (liftIO . removeWhenExistsWith R.removeLink)
 			showNote "using youtube-dl"
 			Transfer.notifyTransfer Transfer.Download url $
-				Transfer.download' webUUID mediakey (AssociatedFile Nothing) Transfer.noRetry $ \p ->
+				Transfer.download' webUUID mediakey (AssociatedFile Nothing) Nothing Transfer.noRetry $ \p ->
 					youtubeDl url (fromRawFilePath workdir) p >>= \case
 						Right (Just mediafile) -> do
 							cleanuptmp
@@ -396,7 +396,7 @@ downloadWith' downloader dummykey u url afile =
 	checkDiskSpaceToGet dummykey Nothing $ do
 		tmp <- fromRepo $ gitAnnexTmpObjectLocation dummykey
 		ok <- Transfer.notifyTransfer Transfer.Download url $
-			Transfer.download' u dummykey afile Transfer.stdRetry $ \p -> do
+			Transfer.download' u dummykey afile Nothing Transfer.stdRetry $ \p -> do
 				createAnnexDirectory (parentDir tmp)
 				downloader (fromRawFilePath tmp) p
 		if ok

Command/Export.hs

@@ -287,7 +287,7 @@ performExport r db ek af contentsha loc allfilledvar = do
 				-- could be used for more than one export
 				-- location, and concurrently uploading
 				-- of the content should still be allowed.
-				alwaysUpload (uuid r) k af stdRetry $ \pm -> do
+				alwaysUpload (uuid r) k af Nothing stdRetry $ \pm -> do
 					let rollback = void $
 						performUnexport r db [ek] loc
 					sendAnnex k rollback $ \f ->

Command/SendKey.hs

@@ -50,7 +50,7 @@ fieldTransfer direction key a = do
 		<$> Fields.getField Fields.associatedFile
 	ok <- maybe (a $ const noop)
 		-- Using noRetry here because we're the sender.
-		(\u -> runner (Transfer direction (toUUID u) (fromKey id key)) afile noRetry a)
+		(\u -> runner (Transfer direction (toUUID u) (fromKey id key)) afile Nothing noRetry a)
 		=<< Fields.getField Fields.remoteUUID
 	liftIO $ debugM "fieldTransfer" "transfer done"
 	liftIO $ exitBool ok

Command/TransferKey.hs

@@ -51,7 +51,7 @@ start o (_, key) = startingCustomOutput key $ case fromToOptions o of
 
 toPerform :: Key -> AssociatedFile -> Remote -> CommandPerform
 toPerform key file remote = go Upload file $
-	upload' (uuid remote) key file stdRetry $ \p -> do
+	upload' (uuid remote) key file Nothing stdRetry $ \p -> do
 		tryNonAsync (Remote.storeKey remote key file p) >>= \case
 			Right () -> do
 				Remote.logStatus remote key InfoPresent
@@ -62,7 +62,7 @@ toPerform key file remote = go Upload file $
 
 fromPerform :: Key -> AssociatedFile -> Remote -> CommandPerform
 fromPerform key file remote = go Upload file $
-	download' (uuid remote) key file stdRetry $ \p ->
+	download' (uuid remote) key file Nothing stdRetry $ \p ->
 		logStatusAfter key $ getViaTmp (retrievalSecurityPolicy remote) (RemoteVerify remote) key file $ \t ->
 			tryNonAsync (Remote.retrieveKeyFile remote key file (fromRawFilePath t) p) >>= \case
 				Right v -> return (True, v)	

Command/TransferKeys.hs

@@ -40,7 +40,7 @@ start = do
   where
 	runner (TransferRequest direction remote key file)
 		| direction == Upload = notifyTransfer direction file $
-			upload' (Remote.uuid remote) key file stdRetry $ \p -> do
+			upload' (Remote.uuid remote) key file Nothing stdRetry $ \p -> do
 				tryNonAsync (Remote.storeKey remote key file p) >>= \case
 					Left e -> do
 						warning (show e)
@@ -49,7 +49,7 @@ start = do
 						Remote.logStatus remote key InfoPresent
 						return True
 		| otherwise = notifyTransfer direction file $
-			download' (Remote.uuid remote) key file stdRetry $ \p ->
+			download' (Remote.uuid remote) key file Nothing stdRetry $ \p ->
 				logStatusAfter key $ getViaTmp (Remote.retrievalSecurityPolicy remote) (RemoteVerify remote) key file $ \t -> do
 					r <- tryNonAsync (Remote.retrieveKeyFile remote key file (fromRawFilePath t) p) >>= \case
 						Left e -> do

Command/Transferrer.hs

@@ -45,21 +45,23 @@ start = do
 	runner (UploadRequest _ key (TransferAssociatedFile file)) remote =
 		-- This is called by eg, Annex.Transfer.upload,
 		-- so caller is responsible for doing notification,
-		-- and for retrying, and updating location log.
-		upload' (Remote.uuid remote) key file noRetry
+		-- and for retrying, and updating location log,
+		-- and stall canceling.
+		upload' (Remote.uuid remote) key file Nothing noRetry
 			(Remote.action . Remote.storeKey remote key file)
 			noNotification
 	runner (DownloadRequest _ key (TransferAssociatedFile file)) remote =
 		-- This is called by eg, Annex.Transfer.download
 		-- so caller is responsible for doing notification
-		-- and for retrying, and updating location log.
+		-- and for retrying, and updating location log,
+		-- and stall canceling.
 		let go p = getViaTmp (Remote.retrievalSecurityPolicy remote) (RemoteVerify remote) key file $ \t -> do
 			Remote.verifiedAction (Remote.retrieveKeyFile remote key file (fromRawFilePath t) p)
-		in download' (Remote.uuid remote) key file noRetry go 
+		in download' (Remote.uuid remote) key file Nothing noRetry go 
 			noNotification
 	runner (AssistantUploadRequest _ key (TransferAssociatedFile file)) remote =
 		notifyTransfer Upload file $
-			upload' (Remote.uuid remote) key file stdRetry $ \p -> do
+			upload' (Remote.uuid remote) key file Nothing stdRetry $ \p -> do
 				tryNonAsync (Remote.storeKey remote key file p) >>= \case
 					Left e -> do
 						warning (show e)
@@ -69,7 +71,7 @@ start = do
 						return True
 	runner (AssistantDownloadRequest _ key (TransferAssociatedFile file)) remote =
 		notifyTransfer Download file $
-			download' (Remote.uuid remote) key file stdRetry $ \p ->
+			download' (Remote.uuid remote) key file Nothing stdRetry $ \p ->
 				logStatusAfter key $ getViaTmp (Remote.retrievalSecurityPolicy remote) (RemoteVerify remote) key file $ \t -> do
 					r <- tryNonAsync (Remote.retrieveKeyFile remote key file (fromRawFilePath t) p) >>= \case
 						Left e -> do