No, and there never will be.

Yes.

bit 4 is BIP 91. BIP 9 is the generic versionbits signaling system. BIP 9 is what segwit uses; BIP 91 is a modified version of BIP 9.

There is no need to wait for august 1st to install and run anything. In fact, august 1st is probably a horrible time to do that since BIP 91 activates tomorrow. To best avoid seeing blockchain reorgs, you should build and run the segsignal patch of Bitcoin Core. The code that you should build is available here: https://github.com/segsignal/bitcoin

If there is a fork and you have an unconfirmed transaction created and sent before the fork, your transaction will likely be able to be confirmed on all chains following the fork. This means that you will have coins on all forks. However you should not trust the confirmations that you see for your transaction until it has several tens of confirmations. This is because the chain that you are looking at could, at any time, be potentially wiped out and replaced by a different chain. If that other chain does not have your transaction confirmed in it, then your transaction will become unconfirmed again.

Also, it is important to note that August 1st is not the only time that a fork can occur. With false signalling and spy mining, BIP 91 (which just locked in) could cause forks once it activates.

Segwit is a capacity increase proposal which includes various fixes for many things in Bitcoin. It is a soft fork and has its own deployment parameters. Segwit can only be activated if 1915 blocks out of a 2016 difficulty retarget period signal for segwit. Signaling for segwit means that once segwit activates, those miners will enforce segwit's consensus rules. Signaling is done by setting bit 1 of the 32 bit block version number.

BIP 148 is a method to get segwit deployed. When it activates, all blocks must signal for segwit on bit 1 so that segwit will activate by its own deployment procedure. BIP 148 activates when the median time past (the median timestamp of the last 11 blocks) is at or after August 1st, 00:00 UTC. There is no miner signaling and it requires that many users and miners enforce the consensus rule change to force miners to mine the blocks that the users want.

BIP 91 is a another method to get segwit deployed. When it activates, like BIP 148, BIP 91 requires that all blocks must signal for segwit on bit 1 so that segwit will be activated by its own deployment procedure. BIP 91 activates when 269 blocks out of a 336 block non-overlapping window signal for BIP 91. Miners signal for BIP 91 by setting bit 4 of the block version number. Signaling for BIP 91 means that miners will enforce BIP 91's consensus rules.

BIP 149 is a plan to redeploy segwit after it reaches its timeout. Segwit's current deployment will expire on November 15th. BIP 149 is a proposal to redeploy segwit with new deployment parameters after November 15th. It specifies that miners can signal for segwit on bit 1 and activate segwit via miner signaling like they can do now with segwit's current deployment. However once BIP 149's timeout is reached (July 4th 2018), if segwit has not activated yet, segwit will then activate at the given timeout.

Segwit2x is a combination of BIP 91 and a hard fork. Segwit2x currently is implemented as first activating segwit via the BIP 91 method, and then 12960 blocks after segwit activates, hard fork from the 4 MB block weight specified by segwit to an 8 MB block weight.

On August 1st at the time that everyone is so fixated on, probably 0. However the probability of a fork between now and the end of August is almost guaranteed. But you are asking us to predict the future, and that is impossible to do.

Electrum allows you to connect to an electrum server that you want to use so you can choose the chain you want to use. If you end up on a chain that you don't want to use, you can switch to using a different server and use the chain that you do want to use.

Now that BIP 91 has almost locked in, once it activates, it will hopefully make BIP 148 a non-event. However there is risk that enforcement does not happen for BIP 91 and BIP 148 may still happen. Even if BIP 91 is enforced, there may be many smaller forks since not 100% of the hash power is signaling BIP 91 and thus may end up mining BIP 91 invalid blocks. These invalid blocks could be briefly extended upon by spy mining and by other non-BIP 91 miners thus resulting in a fork. Such forks would likely be reorged out but they may happen multiple times, so we would end up with several mini-forks that go away.

BIP 149 and Segwit2x are unnecessary for segwit to activate.

BIP 141 specifies the actual signaling that needs to be done for segwit to activate. This method is that 1916 out of a 2016 block window must set bit 1 before segwit can become locked in. BIP 148 and segwit2x are mechanisms to force miners to signal bit 1 so that segwit can activate.

Yes. Once BIP 91 is activated, all miners must then signal for segwit on bit 1 so that segwit can be locked in and then later activate.

No, that is completely wrong. BIP 148 is completely unrelated to BIP 91. BIP 91 is part of segwit2x, not the other way around.

If BIP 91 activates, then there is no need for BIP 148. BIP 148 will still activate on August 1st, but if BIP 91 activates and is enforced by that time, both BIP 148 and BIP 91 will be following the same consensus rules (that all blocks must signal for segwit) so there will be no split.

Coins will not disappear. However the exchange may decide to use a chain which you do not want to use, and thus prevent you from using coins that you do want to use.

That is incorrect. There can still be one or more splits. However these splits may not be persistent. Those miners who are not following the BIP 91 rules will find their block orphaned. Since there may be 20% or more (because of variance, BIP 91 could activate without 80%) of miners who are not following the BIP 91 rules, they could end up mining a small fork of the chain briefly before the rest of the miners mine a chain longer than theirs and causes a reorg. Furthermore, with the prevalence of spy mining, miners who are enforcing BIP 91 may accidentally end up extending a non-BIP 91 chain because they are mining before validating.

The same issue would happen if BIP 148 had majority hash rate support, but because it does not, BIP 148 would likely result in a persistent two chain split.

You are asking us to predict the future; we can't do that. BIP 91 currently has almost 80% hash rate support. With some luck and variance, it could activate soon. Whether it actually does waits to be seen. We cannot predict the future.

Furthermore, even if BIP 91 does activate, miners may not be actually enforcing it so it may not even activate segwit.

If BIP 91 activates, then it will require all blocks to signal for segwit. This is the same as what BIP 148 requires after August 1st, so, assuming that there are no chain splits because of BIP 91, BIP 148 nodes will follow the same chain, and after August 1st, both will be enforcing the same rules.

Also my website is tracking BIP 91 signaling: https://www.btcforkmonitor.info/ as well as monitoring for any chain splits.

This thread is talking about neither of those things. BIP 91 is unrelated to UASF or UAHF. Neither the UASF or the UAHF will trigger the warning that you see here as they do not do miner signaling; rather they activate via flag day. However BIP 91 activates via miner signaling, so we get the warning here about that.

Multiple chain splits can occur when the 80% of miners orphan the blocks of the 20% who are not signaling for segwit. While this may not result in a persistent chain fork, there can and likely will be mini forks and longer orphan chains. This problem is also exacerbated by spy mining (where miners begin building on a new block before validating it) and by the short confirmation window of BIP 91. The short window means that BIP 91 could activate with less than 80% hash rate support.

Your questions is incredibly vague. Can you please be more specific? Can you tell us what wallet software or service you are using?

You are completely missing the nuance. Very few of the Core developers have said that they support BIPs 148/149 with the current political situation. Re-read what those statements say: "Prefer" it is what he would choose if it was only up to him and no outside influences. That means that if BIP 148/149 existed in a vacuum with no outside influence (e.g. from miners) and everyone went along with it, they would prefer that as it is an activation via flag day. Are you seriously that confused about the meaning of written English? Are you seriously misconstruing "prefer" and "acceptable" as meaning "want it now as it is now" even when the definition on the page says otherwise?

Since BIP 148/149 do not exist in a vacuum and they are not the proposals accepted by everyone, nearly all Core developers do not endorse it. There have been three attempts to merge BIP 148 into Core, and all of them have been rejected by the very same people you claim are endorsing BIP 148. Those Core developers are not saying that they are happy with BIP 148/149 as they are now, only that if those were the only two proposals and existed in a vacuum and without any contentiousness that they would then support them.

It's a general information thread about "warnings that you will see" so I put it in Bitcoin Discussion for more visibility.

Read https://bitcointalk.org/index.php?topic=2027513.0

Check out the website here: https://www.btcforkmonitor.info/

This is a website that I put together over the weekend in preparation of potential BIP 91 activation and BIP 148 activation. If the site detects a chain fork, there will be a big red alert at the top saying as such. Each node will also include the block hash and height at which the chain that it is following diverged from another node's chain. In the event of multiple chain forks, the most recent one will be shown for each node.

The website will consider any chain split of 2 or more blocks deep as a chain split. This is to avoid cases of orphaned blocks and of latency between the nodes.

The website will update its data from the nodes every 10 seconds. However you will need to refresh the page to see if there has been any changes.

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The source code for this website is available at https://github.com/achow101/forkmon. Pull requests are welcome.

The website and its source code is licensed under the MIT License.

read https://bitcointalk.org/index.php?topic=2027513.0

yes.

Where am I complaining about the 80% activation threshold? The purpose of this thread is to inform people about the warning that they will see in Core, not complaining about BIP 91.

The table does not explain any nuance and conditions under which people find BIPs 148 or 149 as preferred.

If the majority of Core actually supported BIPs 148 and 149, then BIP 148 support would have been merged into Core, but it has not.

btc1 is the client, not BIP 91. BIP 91 is the proposal. Anyways, by Core, I mean any derivative of Core.