e8171ca7c6
part configs I noticed certain ln payments become very unreliable. These payments are ~21k sat, from gossip to gossip sender, with direct, unannounced channel. Due to the recent fix https://github.com/spesmilo/electrum/pull/9723 `LNPathFinder.get_shortest_path_hops()` will not use channels for the last hop of a route anymore that aren't also passed to it in `my_sending_channels`: ```python if edge_startnode == nodeA and my_sending_channels: # payment outgoing, on our channel if edge_channel_id not in my_sending_channels: continue ``` Conceptually this makes sense as we only want to send through `my_sending_channels`, however if the only channel between us and the receiver is a direct channel that we got from the r_tag and it's not passed in `my_sending_channel` it's not able to construct a route now. Previously this type of payment worked as `get_shortest_path_hops()` knew of the direct channel between us and `nodeB` from the invoices r_tag and then just used this channel as the route, even though it was (often) not contained in `my_sending_channels`. `my_sending_channels`, passed in `LNWallet.create_routes_for_payment()` is either a single channel or all our channels, depending on `is_multichan_mpp`: ```python for sc in split_configurations: is_multichan_mpp = len(sc.config.items()) > 1 ``` This causes the unreliable, random behavior as `LNWallet.suggest_splits()` is supposed to `exclude_single_part_payments` if the amount is > `MPP_SPLIT_PART_MINAMT_SAT` (5000 sat). As `mpp_split.py suggest_splits()` is selecting channels randomly, and then removes single part configs, it sometimes doesn't return a single configuration, as it removes single part splits, and also removes multi part splits if a part is below 10 000 sat: ```python if target_parts > 1 and config.is_any_amount_smaller_than_min_part_size(): continue ``` This will result in a fallback to allow single part payments: ```python split_configurations = get_splits() if not split_configurations and exclude_single_part_payments: exclude_single_part_payments = False split_configurations = get_splits() ``` Then the payment works as all our channels are passed as `my_sending_channels` to `LNWallet.create_routes_for_payment()`. However sometimes this fallback doesn't happen, because a few mpp configurations found in the first iteration of `suggest_splits` have been kept, e.g. [10500, 10500], but at the same time most others have been removed as they crossed the limit, e.g. [11001, 9999], (which happens sometimes with payments ~20k sat), this makes `suggest_splits` return very few usable channels/configurations (sometimes just one or two, even with way more available channels). This makes payments in this range unreliable as we do not retry to generate new split configurations if the following path finding fails with `NoPathFound()`, and there is no single part configuration that allows the path finding to access all channels. Also this does not only affect direct channel payments, but all gossip payments in this amount range. There seem to be multiple ways to fix this, i think one simple approach is to just disable `exclude_single_part_payments` if the splitting loop already begins to sort out configs on the second iteration (the first split), as this indicates that the amount may be too small to split within the given limits, and prevents the issue of having only few valid splits returned and not going into the fallback. However this also results in increased usage of single part payments.
Electrum - Lightweight Bitcoin client
Licence: MIT Licence
Author: Thomas Voegtlin
Language: Python (>= 3.10)
Homepage: https://electrum.org/
Getting started
(If you've come here looking to simply run Electrum, you may download it here.)
Electrum itself is pure Python, and so are most of the required dependencies, but not everything. The following sections describe how to run from source, but here is a TL;DR:
$ sudo apt-get install libsecp256k1-dev
$ ELECTRUM_ECC_DONT_COMPILE=1 python3 -m pip install --user ".[gui,crypto]"
Not pure-python dependencies
Qt GUI
If you want to use the Qt interface, install the Qt dependencies:
$ sudo apt-get install python3-pyqt6
libsecp256k1
For elliptic curve operations, libsecp256k1 is a required dependency.
If you "pip install" Electrum, by default libsecp will get compiled locally,
as part of the electrum-ecc dependency. This can be opted-out of,
by setting the ELECTRUM_ECC_DONT_COMPILE=1 environment variable.
For the compilation to work, besides a C compiler, you need at least:
$ sudo apt-get install automake libtool
If you opt out of the compilation, you need to provide libsecp in another way, e.g.:
$ sudo apt-get install libsecp256k1-dev
cryptography
Due to the need for fast symmetric ciphers, cryptography is required. Install from your package manager (or from pip):
$ sudo apt-get install python3-cryptography
hardware-wallet support
If you would like hardware wallet support, see this.
Running from tar.gz
If you downloaded the official package (tar.gz), you can run Electrum from its root directory without installing it on your system; all the pure python dependencies are included in the 'packages' directory. To run Electrum from its root directory, just do:
$ ./run_electrum
You can also install Electrum on your system, by running this command:
$ sudo apt-get install python3-setuptools python3-pip
$ python3 -m pip install --user .
This will download and install the Python dependencies used by
Electrum instead of using the 'packages' directory.
It will also place an executable named electrum in ~/.local/bin,
so make sure that is on your PATH variable.
Development version (git clone)
(For OS-specific instructions, see here for Windows, and for macOS)
Check out the code from GitHub:
$ git clone https://github.com/spesmilo/electrum.git
$ cd electrum
$ git submodule update --init
Run install (this should install dependencies):
$ python3 -m pip install --user -e .
Create translations (optional):
$ sudo apt-get install gettext
$ ./contrib/locale/build_locale.sh electrum/locale/locale electrum/locale/locale
Finally, to start Electrum:
$ ./run_electrum
Run tests
Run unit tests with pytest:
$ pytest tests -v
To run a single file, specify it directly like this:
$ pytest tests/test_bitcoin.py -v
Creating Binaries
Contributing
Any help testing the software, reporting or fixing bugs, reviewing pull requests and recent changes, writing tests, or helping with outstanding issues is very welcome. Implementing new features, or improving/refactoring the codebase, is of course also welcome, but to avoid wasted effort, especially for larger changes, we encourage discussing these on the issue tracker or IRC first.
Besides GitHub,
most communication about Electrum development happens on IRC, in the
#electrum channel on Libera Chat. The easiest way to participate on IRC is
with the web client, web.libera.chat.