Node A mines past the pruning depth at the fast-time profile (finality 120, pruning 4,600), a fresh node B joins
by headers proof; PASS = B takes A's sink with the 1026 header version. --window sets the sampled difficulty
window in samples: 150 (the minimum, 600 DAA) by default; 661 (the devnet's, 2,644 DAA) is the known-failed
shape found on the first run (7 October 2026, 04:45 to 05:55 UK): B's walk through the sampled trusted blocks
ran out before genesis and "DAA window data has only 180 entries" ended the IBD, then the N6 guard banned the
syncer on each retry. The node fix is e3798a17 on ca3-v4-0318 (a young chain's short window is legal when the
walk reached the chain's start); the devnet and the testnet never meet the shape (pruning samples at multiples
of the 43,200 finality depth).
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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