demo-chains-sync: blockfetch demo is broken

[coot]

I tried to run blockfetch demo and I noticed that the server is hitting an assertion exception:

cabal run demo-chain-sync -- blockfetch client +RTS -l -RTS
Up to date
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cur chain  : (Origin,Origin)
demo-chain-sync: Assertion failed
CallStack (from HasCallStack):
  assert, called at src/Ouroboros/Network/BlockFetch/State.hs:184:5 in ouroboros-network-0.1.0.0-inplace:
Ouroboros.Network.BlockFetch.State
CallStack (from -prof):
  Ouroboros.Network.BlockFetch.State.fetchLogicIterations (src/Ouroboros/Network/BlockFetch/State.hs:(66,
1)-(83,24))
  Ouroboros.Network.BlockFetch.blockFetchLogic (src/Ouroboros/Network/BlockFetch.hs:(237,1)-(293,29))
  Control.Concurrent.Async.async (Control/Concurrent/Async.hs:194:1-35)
  System.IOManager.withIOManager (src/System/IOManager.hs:63:1-51)
  Main.clientBlockFetch (demo/chain-sync.hs:(251,1)-(394,74))
  Main.main (demo/chain-sync.hs:(73,1)-(103,25))

[yangl1996]

Hi there, is there any update on this issue? I played with this demo a bit and noticed that FetchedBlocks is not being updated. https://github.com/input-output-hk/ouroboros-network/blob/master/ouroboros-network/demo/chain-sync.hs#L731

(I removed the two assertions in the error message from @coot . Otherwise the demo crashed upon start.)

[coot]

no update yet, it's a low priority at the moment.