sui

How far back this chain can be debugged

Stepping a transaction means re-executing it, and that needs the state the chain was in just before it ran. On this chain it is obtainable at block 28845373 and above, and not below. THAT IS A LIMIT ON WHAT CAN BE RECORDED, not on what is published here. A transaction already recorded carries its own execution and steps from it for good; the boundary says that a transaction below it cannot be recorded NOW, because the state a replay would have to start from is not reachable by the pipeline that records this chain. The sentence below is that pipeline's own record of what it measured.

Of the 20 transactions recorded here, none steps at source level, which needs verified source and debug information for every contract a transaction ran, and 20 step one VM instruction at a time. A debug tier belongs to each recording rather than to the chain, so this counts what was recorded and promises nothing about the next transaction.

How that boundary was established, in the pipeline's own words: “checkpoint 28845373 is the first at protocol version 38, the first Sui execution layer with trace hooks; a transaction below it still replays but writes no trace. The chain's state is not the limit: each transaction names the exact object versions it consumed, and the GraphQL service served their contents down to checkpoint 1000000 when last measured”

How each trace on this chain is checked, in the pipeline's own words: “each transaction is re-executed by `sui replay` from the exact object versions it consumed and compared with the effects the chain recorded (status, the four gas components, the events digest and the Lamport version); one that does not match is published as divergent, never as a trace of the chain, and one that cannot be traced is refused with its reason. The source shown is the bytecode disassembly of the packages that ran, read from chain state”