uci question, receive stop before pondering starts

[xr_a_y]

I have a bug in Minic. It is as follow :
- "go ponder" is received
- "stop" is received even before ID loop has started.

So I have no move to return... and thus write nothing to standard output (no bestmove)
It seems the GUI is waiting for something to be written in this case.
What are you doing ?
Is this the solution ?

Code: Select all

bestmove 0000

[xr_a_y]

At least it works.

So I conclude that, even when engine is pondering, GUI are expecting a "bestmove" line even if there is no best move.

This looks fair anyway. My bad.

[Werner Taelemans]

What are you doing ?
Is this the solution ?

Code: Select all

bestmove 0000

UCI says:

Code: Select all

  * stop 
        stop calculating as soon as possible,
        don't forget the "bestmove" and possibly the "ponder" token when finishing the search
 

So, you don't have to stop immediately. You can complete the first iteration and return the best move. That's what I do.

[xr_a_y]

UCI says:

Code: Select all

  * stop 
        stop calculating as soon as possible,
        don't forget the "bestmove" and possibly the "ponder" token when finishing the search
 

So, you don't have to stop immediately. You can complete the first iteration and return the best move. That's what I do.

That seems like a good advice !

It seems just sending bestmove 0000 is doing the trick while receivin stop during pondering but it looks clean to at least finish depth 1.

[hgm]

The GUI will not look at the move when it interrupts a ponder search, because the move is useless (not made from the current position). Otherwise it would have sent 'ponderhit'.

[Werner Taelemans]

The GUI will not look at the move when it interrupts a ponder search, because the move is useless (not made from the current position). Otherwise it would have sent 'ponderhit'.

Yes.
I forgot that UCI also accepts nullmoves:

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 A nullmove from the Engine to the GUI should be sent as 0000. 

So, yes, "bestmove 0000" is a perfect solution.