The rules say this in version 1.0:
Ending the game:
If any of the below victory conditions are true, the game is over:
* If a player's causes their opponent to be in a position where their opponent is unable to legally sow any pieces on
any columns on the board, that player wins the game.
A question arose if a player has no legal ability to enter pieces onto the board. If this is the case, then the player who is unable to perform a legal move, loses the game.