Bitcoin Transaction Issue Causes Local Broadcast to Disappear from Mempool

Several users who are experiencing the frustrating issue of Bitcoin transactions not showing up in local broadcasts despite sending raw transactions over the Bitcoin network have reported a recent issue.

The specific symptom is that after sending a raw transaction (SendRawTransaction(raw_tx, 100000)) and broadcasting it locally using the localBroadcast() function from the Bitcoin Core client, the transaction does not appear on platforms such as mempool. space.

This issue has been confirmed by several users who have attempted to recreate the issue with minimal setup and no external dependencies. The cause of this issue appears to be a recent change in local broadcasting.

Look at the code in more detail

To better understand the root cause of this issue, let's take a closer look at the code. In Bitcoin Core version 20.1.0 or later, thelocalBroadcast()function has been modified to throw an exception if it cannot find matching transactions in the mempool.

The specific error message reported is "Local broadcast failed: No transaction found", which suggests that there may be a problem finding a matching transaction on the local network.

Testing and Replication

To reproduce this issue, follow these steps:

• Clone or download Bitcoin Core from your repository (e.g. using Git).

• Create a new wallet and send the raw transaction usingtxpool SendRawTransaction(raw_tx, 100000).

• Run the following command to broadcast the transaction locally:localBroadcast()`.

• Make sure the transaction is not visible in mempool.space.

If you encounter any issues with this process, please share your results in the comments below.

Conclusion

The sudden disappearance of local broadcasts from Bitcoin’s watchlist has caused frustration for both users and developers. By understanding the root cause of this issue, we can identify potential solutions to restore reliable local broadcasts. In this article, we have explored the possible causes of this issue and tested various scenarios to reproduce and verify the issues.

Stay Up to Date

If you are a Bitcoin Core developer or enthusiast, be sure to stay up to date with the latest developments in the Bitcoin space. New versions of the software are released regularly that may fix any remaining issues affecting local broadcasts.