OrbifxGiven Lwt's functionality, I don't think it's critical either.
slekamlOh sorry I mistook this chan for the chan of the people who took the ocaml mooc
Other hint : I have a periodic (debug) task which prints dots :
let rec loop () = Lwt_io.printf "." ;%lwt Lwt_unix.sleep 0.1 ;%lwt loop ()
As the FLUSH blocks, this loop may block or not (same executable launched a couple of times : once it prints dots repeatedly, but FLUSH is blocked, once it does not print dots and FLUSH is also blocked).
Lwt_bytes.writewould have to hang, emptying the internal
Lwt_iochannel buffer. I suggest to either narrow the case as much as you can, by deleting huge chunks of code from a second copy of your project, or to put lwt as a sibling project of yours into a dune workspace and instrument
Lwt_iowith prints to get a better idea of what is going on