SyncStop Ponder Issue

[d3vv]

Cfish has an issue with some gui/cli interfaces... If we have this issue via interface based by polyglot [ https://github.com/ddugovic/polyglot ] we need to set "SyncStop = true":

       SyncStop (default: false)
           When a ponder miss occurs, Polyglot interrupts the engine and
           IMMEDIATELY launches a new search.  While there should be no
           problem with this, some engines seem confused and corrupt their
           search board.  "SyncStop" forces PolyGlot to wait for the (now
           useless) ponder search to finish before launching the new search.

[syzygy1]

What happens when Cfish gets confused? Does it freeze?

[d3vv]

it may be unresponsive (seems like infinite ponder into background) or return illegal move on new game.. you could to test this issue with Crafty Chess Interface [ https://sourceforge.net/projects/craftychessinterface/ ] which uses polyglot external binaries..

[syzygy1]

I suppose this is still a problem?

If I understand correctly, the problem occurs if Cfish is pondering and receives a "stop" command immediately followed by a "position" command and another "go" command.

Unfortunately I cannot easily reproduce the problem from the command line either with a Linux binary or with a Windows binary (under Wine), even if I copy & paste the stop, position and go commands in one action.