Note that the lib string provided to lanes.gen can only specify standard libraries. If you want to pre-require anything else, you have to provide a table like so:
task = lanes.gen("*", {required={"socket"}}, function() ... end)
where "*" means all libs (you need to load "package" to be able to require stuff in the 'required' list).
Here is what I obtain when I try (windows 10 x64):
Lua 5.4.4 Copyright (C) 1994-2022 Lua.org, PUC-Rio
> lanes = require "lanes".configure()
> socket = lanes.require "socket"
> =socket
table: 000002054E67F190
> task = lanes.gen("*", {required={"socket"}}, function(t) print("got: ", t) end)
> task(socket)
Lane: 000002054E72E768
> got: table: 000002054E70D740
Possibly this is caused by some missing path/cpath in your setup?
Benoit.