Fix fastforward CLI

src/cli/blockchain_cli_peer.erl

@@ -450,8 +450,21 @@ peer_fastforward(["peer", "fastforward", Addr], [], []) ->
     SwarmTID = blockchain_swarm:tid(),
     TrimmedAddr = string:trim(Addr),
     case blockchain_fastforward_handler:dial(SwarmTID, Chain, TrimmedAddr) of
-        {ok, _Pid} ->
-            [clique_status:text("ok")];
+        {ok, Stream} ->
+            Ref = erlang:monitor(process, Stream),
+            %% sleep for a moment because there can be a race in monitor
+            timer:sleep(100),
+            receive
+                {'DOWN', Ref, process, Stream, normal} ->
+                    %% we're done, nothing to do here.
+                    [clique_status:text("ok")];
+                {'DOWN', Ref, process, Stream, Reason} ->
+                    Text = io_lib:format("fastforward failed with error ~p", [Reason]),
+                    [clique_status:text(Text)]
+            after timer:minutes(application:get_env(blockchain, sync_timeout_mins, 5)) ->
+                    libp2p_framed_stream:close(Stream),
+                    [clique_status:text("fastforward timeout")]
+            end;
         {error, Reason} ->
             Text = io_lib:format("Failed to connect to ~p: ~p", [TrimmedAddr, Reason]),
             [clique_status:alert([clique_status:text(Text)])]