Error on search, no root children

[dkappe]

position startpos moves c2c4 c7c5 h2h3 g7g6 b1c3 b8c6 e2e3 f8g7 g1f3 g8f6 d2d4 c5d4 e3d4 d7d5 c1e3 e8g8 f1e2 d5c4 e2c4 d8d6 e1g1 c6a5 c4e2 b7b6 f3e5 c8b7 c3b5 d6d8 d1a4 f6d5 b5c3 d5c3 b2c3 a8c8 a1c1 d8d5 e2f3 d5e6 f3b7 a5b7 a4a7 g7e5 d4e5 b7c5 c1b1 c8a8 a7b6 e6b6 b1b6 f8c8 e3c5 c8c5 e5e6 a8a2 b6b7 g8f8 e6f7 c5c3 b7e7 f8e7 f7f8r e7f8 g2g3 h7h5 g1g2 c3c2 h3h4 f8g7 g2g1 c2d2 g1g2 a2b2 g2g1 b2a2 g1g2 d2c2 g2g1 g7f7 g1g2

        bestmove, node = max(
            root.children.items(), key=lambda item: (item[1].policy, item[1].Q())
        )

was able to reproduce the bug finally. It complains that root.children.items() is empty

[dkappe]

Looks like a bug in python-chess. bd.is_game_over(claim_draw=True)) gives True.

chess==1.3.0