fix first sub epoch

Author: almogdepaz

chia/consensus/make_sub_epoch_summary.py

@@ -49,26 +49,13 @@ def make_sub_epoch_summary(
     # This is not technically because more blocks can potentially be included than 2*MAX_SUB_SLOT_BLOCKS,
     # But assuming less than 128 overflow blocks get infused in the first 2 slots, it's not an issue
     if (blocks_included_height + constants.MAX_SUB_SLOT_BLOCKS) // constants.SUB_EPOCH_BLOCKS <= 1:
-        prev_block = blocks.height_to_block_record(blocks_included_height)
-        prev_tx_block = pre_sp_tx_block_height(
-            constants=constants,
-            blocks=blocks,
-            prev_b_hash=prev_block.prev_hash,
-            sp_index=sp_index,
-            first_in_sub_slot=True,
-        )
-        challenge_root = (
-            compute_challenge_merkle_root(constants, blocks, blocks_included_height)
-            if prev_tx_block >= constants.HARD_FORK2_HEIGHT
-            else None
-        )
         return SubEpochSummary(
             constants.GENESIS_CHALLENGE,
             constants.GENESIS_CHALLENGE,
             uint8(0),
             None,
             None,
-            challenge_root,
+            None,  # No challenge root in first sub-epoch
         )
     if prev_ses_block is None:
         curr: BlockRecord = prev_prev_block