ReadAsyncHangs.fs

open System
open System.Net
open FSharp.Control.Tasks
open Pipelines.Sockets.Unofficial

use client = new TcpClient("127.0.0.1", 9851)
let pipe = StreamConnection.GetDuplex(client.GetStream())
let scan = Encoding.UTF8.GetBytes "*2\r\n$4\r\nSCAN\r\n$36\r\n85AB427D-316C-4BD4-A511-6631851D212E\r\n" |> ReadOnlyMemory
task {
    let! _ = pipe.Output.WriteAsync(scan)
    let mutable isCompleted = false
    while not isCompleted do
        let! res = pipe.Input.ReadAsync()
        for segment in res.Buffer do
            printfn "%s" <| Encoding.UTF8.GetString segment.Span
        pipe.Input.AdvanceTo(res.Buffer.Start, res.Buffer.End)
        isCompleted <- res.IsCompleted
    do! pipe.Input.CompleteAsync()
}
|> Async.AwaitTask
|> Async.RunSynchronously