From: "'Angelo' via Bitcoin Development Mailing List" <bitcoindev@googlegroups.com>
To: "bitcoindev@googlegroups.com" <bitcoindev@googlegroups.com>
Subject: [bitcoindev] Re: [bitcoin-dev] Unbreaking testnet4
Date: Sun, 18 Jan 2026 17:26:44 +0000 [thread overview]
Message-ID: <85djL2Ah0Mh9Appt934138jLRE23gGmaIr96y8q-clEmMa_APPZLerKrrUZN524_Diq4pOydQLaEOZ3XBy4-sQIPxYODOHreM5RWuNHILto=@protonmail.com> (raw)
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Hello mailing list.
I have forked Bitcoin Core and modified the code to fix testnet4 by disabling the min difficulty rule after block 150,000: https://github.com/bitcoin/bitcoin/compare/master...batmanbytes:bitcoin:testnet4-fix
The changes in the code are minimal. As I've written in [Bitcointalk](https://bitcointalk.org/index.php?topic=5569103.msg66301279#msg66301279):
> I have introduced int nMinDifficultyBlocksForkHeight which is 0 by default in consensus/params.h, only ever used by the CTestNet4Params class. GetNextWorkRequired and PermittedDifficultyTransition are also modified to check whether min difficulty blocks are enabled, and if yes, whether nMinDifficultyBlocksForkHeight is 0 (which would indicate it is not testnet4).
With no other changes to the code, during the epoch that includes block 150,000 (which already began at block 149,184), we should expect the block interval to increase by roughly sixfold (to about one hour per block). This is because the effective hashrate would correspond to approximately one-sixth of the difficulty. The difficulty increases by about 6x since there are roughly six times more difficulty-1 blocks than blocks at the normal difficulty.
We could modify the code to not suffer from the temporary 1-hour block interval if needed. I'm just interested to see what you think of those changes, so that we can move forward.
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next reply other threads:[~2026-01-18 23:35 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-18 17:26 'Angelo' via Bitcoin Development Mailing List [this message]
2026-01-19 8:40 ` Saint Wenhao
2026-01-22 10:56 ` 'Angelo' via Bitcoin Development Mailing List
[not found] ` <QivViO7YYXUY_b7I-HibvzwD9dftAUl8Yv4nOSRzlCeY12fdtLC5TcAWtqPodMnBeRQ73WPj_OtrSvWlO5mHyQpRYdWbwvslVtxBHJpSqO8=@protonmail.com>
2026-01-26 11:36 ` 'Angelo' via Bitcoin Development Mailing List
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