Lichess UI disconnects from Lichess External Engine if the server connection fails

[Siderite]

So this is the updated version of the bug.

If the call to the server https://engine.lichess.ovh/api/external-engine fails (in my case with 503 Service unavailable), then trying to change the analysed move or stop the analysis or to close the page fails.

I don't know if that's the only way the app can communicate with the lichess UI, but there has to be a workaround for this in case the server is unavailable, like a button in the app to forcefully stop the analysis.

The workaround for me was to restart the app. Sometimes the situation would fix itself after a while (probably because it could restore the connection to the server) and sometimes the UI would report to be unable to connect, but it didn't always work. The 503 errors always appeared in the console as errors.

[Siderite]

New detail: the response content of the 503 responses is "provider did not pick up work"

[Siderite]

Question: why does the local evaluation engine in the lichess website need to go to the lichess API at all?

[fitztrev]

Thanks for the report. I haven't had this happen yet but I will try to recreate it.

[niklasf]

Question: why does the local evaluation engine in the lichess website need to go to the lichess API at all?

It's designed so that third-party providers can offer external engines in other ways. Local engines are just one (important) special case.