try waiting for remote isready

Author: IanButterworth

test/distributed_exec.jl

@@ -218,6 +218,10 @@ for i in 1:max_attempts
 
         @test remotecall_fetch(k->haskey(Distributed.PGRP.refs, k), wid1, fid) == true
 
+        w = timedwait(() -> remotecall_fetch(x->isready(fetch(x)), wid2, fstore), 10)
+        w == :ok || @info "isready timed out on attempt $i (max $max_attempts)"
+        @test w == :ok
+
         testval = remotecall_fetch(wid2, fstore) do x
             try
                 put!(fetch(x), :OK)