Hey guys,

great that you implement external engine use! I wished that for lichess just yesterday. I wanted to ask why a ws is necessary, should not just a regular rest-adapter (in form of a additional layer before UCI) have done the job?

Greetings, Niclas

Hey, I have followed your installation instructions for Ubuntu, however when I open the link there is no dialog asking for authorization. Are there any settings in Lichess that need to be changed? I am using Firefox 105.0 together with Ubuntu 20.04.5 if that helps, remote-uci version is 1.0.0.

Running the tool from the command line produces the following output:

~ remote-uci --engine stockfish        
[2022-10-11T12:09:55Z INFO ] Starting engine "stockfish" ...
[2022-10-11T12:09:55Z INFO ] 0 << uci
[2022-10-11T12:09:56Z WARN ] 0 >> Stockfish 15 by the Stockfish developers (see AUTHORS file)
[2022-10-11T12:09:56Z INFO ] 0 >> id name Stockfish 15
[2022-10-11T12:09:56Z INFO ] 0 >> id author the Stockfish developers (see AUTHORS file)
[2022-10-11T12:09:56Z WARN ] 0 >> 
[2022-10-11T12:09:56Z INFO ] 0 >> option name Debug Log File type string default 
[2022-10-11T12:09:56Z INFO ] 0 >> option name Threads type spin default 1 min 1 max 512
[2022-10-11T12:09:56Z INFO ] 0 >> option name Hash type spin default 16 min 1 max 33554432
[2022-10-11T12:09:56Z INFO ] 0 >> option name Clear Hash type button
[2022-10-11T12:09:56Z INFO ] 0 >> option name Ponder type check default false
[2022-10-11T12:09:56Z INFO ] 0 >> option name MultiPV type spin default 1 min 1 max 500
[2022-10-11T12:09:56Z INFO ] 0 >> option name Skill Level type spin default 20 min 0 max 20
[2022-10-11T12:09:56Z INFO ] 0 >> option name Move Overhead type spin default 10 min 0 max 5000
[2022-10-11T12:09:56Z INFO ] 0 >> option name Slow Mover type spin default 100 min 10 max 1000
[2022-10-11T12:09:56Z INFO ] 0 >> option name nodestime type spin default 0 min 0 max 10000
[2022-10-11T12:09:56Z INFO ] 0 >> option name UCI_Chess960 type check default false
[2022-10-11T12:09:56Z INFO ] 0 >> option name UCI_AnalyseMode type check default false
[2022-10-11T12:09:56Z INFO ] 0 >> option name UCI_LimitStrength type check default false
[2022-10-11T12:09:56Z INFO ] 0 >> option name UCI_Elo type spin default 1350 min 1350 max 2850
[2022-10-11T12:09:56Z INFO ] 0 >> option name UCI_ShowWDL type check default false
[2022-10-11T12:09:56Z INFO ] 0 >> option name SyzygyPath type string default <empty>
[2022-10-11T12:09:56Z INFO ] 0 >> option name SyzygyProbeDepth type spin default 1 min 1 max 100
[2022-10-11T12:09:56Z INFO ] 0 >> option name Syzygy50MoveRule type check default true
[2022-10-11T12:09:56Z INFO ] 0 >> option name SyzygyProbeLimit type spin default 7 min 0 max 7
[2022-10-11T12:09:56Z INFO ] 0 >> option name Use NNUE type check default true
[2022-10-11T12:09:56Z INFO ] 0 >> option name EvalFile type string default nn-6877cd24400e.nnue
[2022-10-11T12:09:56Z INFO ] 0 >> uciok
https://lichess.org/analysis/external?url=ws%3A%2F%2F127.0.0.1%3A9670%2Fsocket&secret=f628a6940430f4e1ca89c1643f617b06&name=Stockfish+15&maxThreads=12&maxHash=8192

Hi, I'm trying to run this but it gets stuck. The command I'm using is:

remote-uci stockfish

When I click the link in the terminal, I see this:

After I authorize and try to open one of my games, it gets stuck like this and never evaluates:

Any suggestions for fixes? This is my log:

[2022-08-19T15:46:23Z WARN ] 0 >> Stockfish 15 by the Stockfish developers (see AUTHORS file)
[2022-08-19T15:46:24Z INFO ] 0 >> id name Stockfish 15
[2022-08-19T15:46:24Z INFO ] 0 >> id author the Stockfish developers (see AUTHORS file)
[2022-08-19T15:46:24Z WARN ] 0 >> 
[2022-08-19T15:46:24Z INFO ] 0 >> option name Debug Log File type string default 
[2022-08-19T15:46:24Z INFO ] 0 >> option name Threads type spin default 1 min 1 max 512
[2022-08-19T15:46:24Z INFO ] 0 >> option name Hash type spin default 16 min 1 max 33554432
[2022-08-19T15:46:24Z INFO ] 0 >> option name Clear Hash type button
[2022-08-19T15:46:24Z INFO ] 0 >> option name Ponder type check default false
[2022-08-19T15:46:24Z INFO ] 0 >> option name MultiPV type spin default 1 min 1 max 500
[2022-08-19T15:46:24Z INFO ] 0 >> option name Skill Level type spin default 20 min 0 max 20
[2022-08-19T15:46:24Z INFO ] 0 >> option name Move Overhead type spin default 10 min 0 max 5000
[2022-08-19T15:46:24Z INFO ] 0 >> option name Slow Mover type spin default 100 min 10 max 1000
[2022-08-19T15:46:24Z INFO ] 0 >> option name nodestime type spin default 0 min 0 max 10000
[2022-08-19T15:46:24Z INFO ] 0 >> option name UCI_Chess960 type check default false
[2022-08-19T15:46:24Z INFO ] 0 >> option name UCI_AnalyseMode type check default false
[2022-08-19T15:46:24Z INFO ] 0 >> option name UCI_LimitStrength type check default false
[2022-08-19T15:46:24Z INFO ] 0 >> option name UCI_Elo type spin default 1350 min 1350 max 2850
[2022-08-19T15:46:24Z INFO ] 0 >> option name UCI_ShowWDL type check default false
[2022-08-19T15:46:24Z INFO ] 0 >> option name SyzygyPath type string default <empty>
[2022-08-19T15:46:24Z INFO ] 0 >> option name SyzygyProbeDepth type spin default 1 min 1 max 100
[2022-08-19T15:46:24Z INFO ] 0 >> option name Syzygy50MoveRule type check default true
[2022-08-19T15:46:24Z INFO ] 0 >> option name SyzygyProbeLimit type spin default 7 min 0 max 7
[2022-08-19T15:46:24Z INFO ] 0 >> option name Use NNUE type check default true
[2022-08-19T15:46:24Z INFO ] 0 >> option name EvalFile type string default nn-6877cd24400e.nnue
[2022-08-19T15:46:24Z INFO ] 0 >> uciok

Whene executing cargo run stockfish within the remote-uci directory and RUST_BACKTRACE=full I get the following warnings and errors

warning: unused import: `ProtocolError`
 --> src/engine.rs:9:18
  |
9 | use crate::uci::{ProtocolError, UciIn, UciOption, UciOptionName, UciOut};
  |                  ^^^^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: field is never read: `variant`
  --> src/engine.rs:18:5
   |
18 |     variant: Variant,
   |     ^^^^^^^^^^^^^^^^
   |
   = note: `#[warn(dead_code)]` on by default

warning: field is never read: `pos`
  --> src/engine.rs:19:5
   |
19 |     pos: VariantPosition,
   |     ^^^^^^^^^^^^^^^^^^^^

warning: `remote-uci` (lib) generated 3 warnings
    Finished release [optimized] target(s) in 30.60s
     Running `target/release/remote-uci stockfish`
thread 'main' panicked at 'spawn engine: Os { code: 2, kind: NotFound, message: "No such file or directory" }', /Users/rkosko/Repos/external-engine/remote-uci/src/lib.rs:87:56
stack backtrace:
   0:        0x1024537b0 - std::backtrace_rs::backtrace::libunwind::trace::hdeda4600dd070bcc
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:        0x1024537b0 - std::backtrace_rs::backtrace::trace_unsynchronized::hc8148713b4dab4e7
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:        0x1024537b0 - std::sys_common::backtrace::_print_fmt::haf0555383873bc65
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/sys_common/backtrace.rs:66:5
   3:        0x1024537b0 - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h1fed2dd6a97f3bed
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/sys_common/backtrace.rs:45:22
   4:        0x10246f958 - core::fmt::write::hb0e4304f3c645902
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/core/src/fmt/mod.rs:1196:17
   5:        0x10244e81c - std::io::Write::write_fmt::h5d1524415c342f9b
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/io/mod.rs:1654:15
   6:        0x102455060 - std::sys_common::backtrace::_print::h048609092df7cfde
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/sys_common/backtrace.rs:48:5
   7:        0x102455060 - std::sys_common::backtrace::print::h4efb3f2f5d6d6b21
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/sys_common/backtrace.rs:35:9
   8:        0x102455060 - std::panicking::default_hook::{{closure}}::ha90997e26eb3c9d7
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panicking.rs:295:22
   9:        0x102454d3c - std::panicking::default_hook::hb89340eaa54105a5
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panicking.rs:314:9
  10:        0x102455538 - std::panicking::rust_panic_with_hook::h1db23d4e5c129198
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panicking.rs:698:17
  11:        0x10245542c - std::panicking::begin_panic_handler::{{closure}}::h18e2e1878436e49e
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panicking.rs:588:13
  12:        0x102453c8c - std::sys_common::backtrace::__rust_end_short_backtrace::h146455e36557ba62
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/sys_common/backtrace.rs:138:18
  13:        0x102455184 - rust_begin_unwind
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panicking.rs:584:5
  14:        0x10248a374 - core::panicking::panic_fmt::hb6f3c1bd9d609721
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/core/src/panicking.rs:142:14
  15:        0x10248a418 - core::result::unwrap_failed::h2b21ee7518c0dc35
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/core/src/result.rs:1785:5
  16:        0x1022cbc3c - remote_uci::main::{{closure}}::h0e8cd6be5c0e29e3
  17:        0x1022e21a4 - tokio::park::thread::CachedParkThread::block_on::h1831e8f8b715e241
  18:        0x1022e23f8 - tokio::runtime::thread_pool::ThreadPool::block_on::h8fdb18da2558717c
  19:        0x1022ff5c4 - tokio::runtime::Runtime::block_on::h0bcab5cb5c7c396f
  20:        0x1022f4510 - remote_uci::main::h05678b5d29931c09
  21:        0x1022daf8c - std::sys_common::backtrace::__rust_begin_short_backtrace::h6c75583e673ad67b
  22:        0x1022ef044 - std::rt::lang_start::{{closure}}::ha82807876cc03ad9
  23:        0x102449fd0 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::hfc87a1b486ea6796
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/core/src/ops/function.rs:280:13
  24:        0x102449fd0 - std::panicking::try::do_call::h7dcb1e4efbfac5dc
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panicking.rs:492:40
  25:        0x102449fd0 - std::panicking::try::h4ee76056fd63c1cd
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panicking.rs:456:19
  26:        0x102449fd0 - std::panic::catch_unwind::hbd5e8ad01dd6a9ee
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panic.rs:137:14
  27:        0x102449fd0 - std::rt::lang_start_internal::{{closure}}::h67dd3aa83aa43833
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/rt.rs:128:48
  28:        0x102449fd0 - std::panicking::try::do_call::h5c2aca003eb2a1cb
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panicking.rs:492:40
  29:        0x102449fd0 - std::panicking::try::h22495619ddde9ed3
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panicking.rs:456:19
  30:        0x102449fd0 - std::panic::catch_unwind::h9c037ef19fbc6aba
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/panic.rs:137:14
  31:        0x102449fd0 - std::rt::lang_start_internal::h609ce79df789091f
                               at /rustc/a8314ef7d0ec7b75c336af2c9857bfaf43002bfc/library/std/src/rt.rs:128:20
  32:        0x1022f45f0 - _main

I wasn't sure if I need to install the stockfish engine separately because it looks to be included in the src. Also I know this is alpha so just was dropping a note if you haven't seen this yet :)

When navigating to http://<external-engine>:<port>, the url query parameter generated and used in the redirect relies on the value supplied by the --bind <BIND> option to the remote-uci command.

In order to facilitate binding the service to Localhost and utilizing a reverse-proxy for handling incoming connections, an option to specify a custom address to be used in the generated ws:// address would be a welcome addition.

Example Scenario

I have deployed the external-engine docker image on a server using the equivalent to the command below. This command essentially provides access to the remote-uci api through a pre-configured Traefik reverse-proxy using the host name stockfish.example.com.

docker run -it --rm \
    --label "traefik.enable=true" \
    --label "traefik.http.routers.stockfish.rule=Host(`stockfish.example.com`)"
    --label "traefik.http.services.stockfish.loadbalancer.server.port=9670" \
    --label "traefik.http.routers.stockfish.tls.certresolver=pdns" \
    -p 127.0.0.1:9670:9670 \
    external-engine \
        /usr/bin/remote-uci --bind 0.0.0.0:9670 --engine stockfish

When navigating to https://stockfish.example.com using the above deployment, the redirect generated contains a url query parameter value that does not work (url=ws://0.0.0.0:9670/socket)

https://lichess.org/analysis/external?url=ws%3A%2F%2F127.0.0.1%3A9670%2Fsocket&secret=<SHHHiTSaSecret>&name=Stockfish+15&maxThreads=8&maxHash=32768

Proposed Solution

Simply adding an optional --external-address command line option that is used to populate the URL template is likely sufficient for 99% of use-cases. An argument could be made for allowing more granular control by having the option to separately set the host and port separately.

I haven't used Rust much in the past but I may take a stab at implementing this feature as an excuse to poke the language a bit.

At first I thought a file was missing from the repo but it turns out to be a powershell syntax error. I fixed it by moving the pipes in Deps.ps1 to the end of the line instead of the beginning.

After running the docker script on Windows, the url it produces is: https://lichess.org/analysis/external?url=ws%3A%2F%2F0.0.0.0%3A9670%2Fsocket&secret=redacted&name=Stockfish+15&maxThreads=8&maxHash=8192

The 0.0.0.0 value doesn't work. Manually changing it to 127.0.0.1 fixes it.

After I run RunDocker.ps1 here's what I get:

PS C:\Users\jonbbbb\dev\external-engine> .\RunDocker.ps1
At C:\Users\jonbbbb\dev\external-engine\Deps.ps1:6 char:1
+ | Where-Object { -Not (Test-Path $(Split-Path $_ -Leaf)) }
+ ~
An empty pipe element is not allowed.
At C:\Users\jonbbbb\dev\external-engine\Deps.ps1:7 char:1
+ | ForEach-Object { Invoke-WebRequest $_ -OutFile $(Split-Path $_ -Lea ...
+ ~
An empty pipe element is not allowed.
    + CategoryInfo          : ParserError: (:) [], ParseException
    + FullyQualifiedErrorId : EmptyPipeElement

[+] Building 0.9s (12/25)
 => [internal] load build definition from Dockerfile                                                               0.0s
 => => transferring dockerfile: 32B                                                                                0.0s
 => [internal] load .dockerignore                                                                                  0.0s
 => => transferring context: 2B                                                                                    0.0s
 => [internal] load metadata for docker.io/library/rust:1.62.0-slim                                                0.3s
 => [internal] load metadata for docker.io/library/debian:bullseye-slim                                            0.3s
 => [internal] load build context                                                                                  0.0s
 => => transferring context: 4.28kB                                                                                0.0s
 => [stockfish 1/8] FROM docker.io/library/debian:bullseye-slim@sha256:5cf1d98cd0805951484f33b34c1ab25aac7007bb41  0.0s
 => CANCELED [remote-uci 1/7] FROM docker.io/library/rust:1.62.0-slim@sha256:8f2e8dc0537dd0e5f0d407ab2c7df2174019  0.5s
 => => resolve docker.io/library/rust:1.62.0-slim@sha256:8f2e8dc0537dd0e5f0d407ab2c7df217401974df95bfee5f95ba1135  0.0s
 => => sha256:8f2e8dc0537dd0e5f0d407ab2c7df217401974df95bfee5f95ba1135a8232fc6 984B / 984B                         0.0s
 => => sha256:91868727ce5f5fdf67966d42f1825af003c2d9fda1066aa161d8eabbe8d4061b 742B / 742B                         0.0s
 => => sha256:278f9d1dd2ba1d3c70802ba1cc4c6bf60de2bbac30283e33877ba401ef92523a 4.85kB / 4.85kB                     0.0s
 => => sha256:461246efe0a75316d99afdbf348f7063b57b0caeee8daab775f1f08152ea36f4 3.15MB / 31.37MB                    0.5s
 => => sha256:efc70690774ac945d5fab061fde25a741314641c293612ee3b1b0b156bb60540 3.15MB / 208.94MB                   0.5s
 => CACHED [stage-3 2/6] RUN apt-get update && apt-get install -y openssl                                          0.0s
 => CACHED [stockfish 2/8] RUN apt-get update && apt-get install -y xz-utils make                                  0.0s
 => CACHED [stockfish 3/8] WORKDIR /stockfish                                                                      0.0s
 => CACHED [stockfish 4/8] COPY stockfish .                                                                        0.0s
 => ERROR [stockfish 5/8] RUN cd vendor &&     sha256sum -c SHA256SUM &&     tar xf sde-external-9.0.0-2021-11-07  0.5s
------
 > [stockfish 5/8] RUN cd vendor &&     sha256sum -c SHA256SUM &&     tar xf sde-external-9.0.0-2021-11-07-lin.tar.xz &&     tar xf x86_64-linux-musl-native.tgz &&     mv nn-6877cd24400e.nnue Stockfish/src:
#11 0.442 sde-external-9.0.0-2021-11-07-lin.tar.xz: FAILED open or read
#11 0.442 x86_64-linux-musl-native.tgz: FAILED open or read
#11 0.442 sha256sum: sde-external-9.0.0-2021-11-07-lin.tar.xz: No such file or directory
#11 0.442 sha256sum: x86_64-linux-musl-native.tgz: No such file or directory
#11 0.442 sha256sum: nn-6877cd24400e.nnue: No such file or directory
#11 0.443 nn-6877cd24400e.nnue: FAILED open or read
#11 0.443 sha256sum: WARNING: 3 listed files could not be read
------
executor failed running [/bin/sh -c cd vendor &&     sha256sum -c SHA256SUM &&     tar xf sde-external-9.0.0-2021-11-07-lin.tar.xz &&     tar xf x86_64-linux-musl-native.tgz &&     mv nn-6877cd24400e.nnue Stockfish/src]: exit code: 1
Unable to find image 'external-engine:latest' locally
docker: Error response from daemon: pull access denied for external-engine, repository does not exist or may require 'docker login': denied: requested access to the resource is denied.
See 'docker run --help'.
PS C:\Users\jonbbbb\dev\external-engine>

Looks like downloads.txt is missing from the repository?

I have remote-uci and stockfish installed from AUR to my laptop (because non-external engine on the analysis board only detects 1 out of my 12 CPU cores). This installation includes a systemd service for the remote uci (and a socket too). After having used https://lichess.org/analysis with the external engine, stockfish ends up hanging in the background with all the memory that has been allocated to it.

I have to sudo systemctl stop remote-uci.service or sudo pkill stockfish if I want to get my RAM back (or, alternatively, go back to the analysis board, and turn engine's memory slider all the way down to 16MB or so).

I have tried different approaches to make the engine stop on its own: closing the tab instead of closing the browser, going to another lichess page, refreshing, turning evaluation off, disconnecting from the remote engine. Nothing seems to help.

I'm not sure whether this is actually an issue or it's just me using the software in an unintended way. Also not sure whether this should go to lila issues or here (and whether the inaccurate detection for the number of CPU cores is a lila issue or just a browser limitation).

Setup

I installed external-engine via the debsource. I modified the config to use lc0 as engine. Lc0 uses the CPU network file, with standard configuration.

Problem

After searching on a position, it continues sending isready and stop commands. It filled my log files (total 40 Go) and broke my root partition.

Hello!

While working on the pull requests submitted recently I found that building the docker image to test changes took up quite a bit of time mainly due to having to build the stockfish binaries.

I ended up making some changes locally that actually made a pretty big difference in both the time it took to build things and also resulted in much smaller image sizes.

Changes

1. Split stockfish off into it's own separate docker image since it doesn't need to be rebuilt (this saves a good amount of time on the initial build) and based the final image on a scratch container that just contains the stockfish binaries and .deb
2. Refactored the external-engine image build to simply copy over the stockfish binaries from it's new image.
3. Switched to using a distroless image for the final layer in external-engine.

Image Size Improvements

Switching over to the distroless image for external-engine resulted in a significant reduction in the size of the final image.

The current docker image that builds both stockfish and external-engine ends comes in around 170Mb.

❯ docker image ls | grep 'fat'
external-engine                     fat-build         b51f1903898c   37 seconds ago      169MB

Switching to the distroless image with just the binaries from external-engine and stockfish cuts that size almost in half.

Note: the distroless-slim image below only has 1 of the 8 stockfish binaries so i'm just adding the two image sizes together for a rough estimate

❯ docker image ls | grep 'distroless-slim\|lichess-org/stockfish'
lichess-org/stockfish               15                88cf4948be4d   38 minutes ago      60.9MB
external-engine                     distroless-slim   e8c28ac942eb   23 hours ago        30.1MB

Hosted Images

My thought process around splitting off the stockfish container was that since it's an external project that doesn't change often, you can remove building it from the external-engine build process by building and pushing it to the Github container registry. That way you are only ever rebuilding the external-engine project itself resulting in significantly faster turnaround time when using a docker based development workflow.

And since the Github build pipeline is already building a container image for external-engine, throwing it up on Githubs container registry will allow users like myself who will only ever deploy it with docker do so without having to build the image at deploy time.

If this is something you'd consider pulling in just let me know and i'll cleanup what I have and submit a PR.

I had some troubles making it run for Windows. For example, python does not like folders with whitespaces like MY NAME FOLDER. Secondly, even more advanced users may not know they have to run pip install. Furthermore, adding enviroment variables in Windows sucks and I think it is more convenient to use --token

Possibly this may involve a larger conversation with Lichess about how analysis is done, but in endgames (or shallow positions in general which search a low node count per depth) it may be desirable to search deeper than 25 plies without resorting to go infinite.