Thanks for adding this to the record. And for the record I’ll reiterate here, as I did with BIP90, that this is a hard fork.
e > On Aug 16, 2019, at 12:06, Peter Todd via bitcoin-dev > <bitcoin-dev@lists.linuxfoundation.org> wrote: > >> On Fri, Aug 16, 2019 at 11:23:37AM -0400, John Newbery via bitcoin-dev wrote: >> Once a consensus change has been activated and buried by sufficient work, >> we consider the height of that change to be historic fact. The exact >> activation method is no longer of practical interest. In some cases the >> cause of activation is not even decidable. For example, we know that segwit >> activated at height 481,824 but it's debatable whether that was due to BIP >> 9 version bits signaling, BIP 148 UASF, or a combination of the two. > > I just wanted to elaborate on this excellent point: > > This is debatable because Bitcoin is a decentralized, soft-forks are backwards > compatible, and it's very difficult if not impossible to measure the > preferences of economically significant nodes. Both the BIP9 version bits > signalling and the BIP 148 UASF had the same basic effect: enforce segwit. > Furthermore, the BIP 148 UASF rejected blocks that didn't signal via the BIP9 > version bits. > > We can observe the fact that 100% of known blocks produced after Aug 1st 2017 > have complied with segwit rules, and the BIP9 signalling protocol for segwit. > But strictly speaking we don't really know why that happened. It's possible > that miners were running the BIP9 signalling Bitcoin Core release around that > time. It's also possible that miners were running UASF enforcing software. > It's possible there was a combination of both. Or even entirely different > software - remember that some miners produced segwit-valid blocks, but didn't > actually mine segwit transactions. Each scenario leads to the same externally > observable outcome. > > Furthermore there's the question as to why miners were producing > segwit-compliant blocks: perhaps they thought the vast majority of > economically > significant nodes would reject their blocks? Perhaps they just wanted to > enforce segwit? > > These are all questions that have plausible answers, backed by evidence and > argument. But because Bitcoin is a decentralized network no authority can tell > you what the answers are. > > -- > https://petertodd.org 'peter'[:-1]@petertodd.org > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev