Skip flakey "concurrent requests" tests on windows

test/runtests.jl

@@ -379,25 +379,31 @@ include("setup.jl")
     end
 
     @testset "concurrent requests" begin
-        mine = Downloader()
-        for downloader in (nothing, mine)
-            have_lsof = Sys.which("lsof") !== nothing
-            count_tcp() = Base.count(x->contains("TCP",x), split(read(`lsof -p $(getpid())`, String), '\n'))
-            if have_lsof
-                n_tcp = count_tcp()
-            end
-            delay = 2
-            count = 100
-            url = "$server/delay/$delay"
-            t = @elapsed @sync for id = 1:count
-                @async begin
-                    json = download_json("$url?id=$id", downloader = downloader)
-                    @test get(json["args"], "id", nothing) == ["$id"]
+        if Sys.iswindows()
+            # Known issue https://github.com/JuliaLang/Downloads.jl/issues/227
+            # These test should be fixed on Windows and then reenabled.
+            @test_skip "concurrent requests flakey on Windows"
+        else
+            mine = Downloader()
+            for downloader in (nothing, mine)
+                have_lsof = Sys.which("lsof") !== nothing
+                count_tcp() = Base.count(x->contains("TCP",x), split(read(`lsof -p $(getpid())`, String), '\n'))
+                if have_lsof
+                    n_tcp = count_tcp()
+                end
+                delay = 2
+                count = 100
+                url = "$server/delay/$delay"
+                t = @elapsed @sync for id = 1:count
+                    @async begin
+                        json = download_json("$url?id=$id", downloader = downloader)
+                        @test get(json["args"], "id", nothing) == ["$id"]
+                    end
+                end
+                @test t < 0.9*count*delay
+                if have_lsof
+                    @test n_tcp == count_tcp()
                 end
-            end
-            @test t < 0.9*count*delay
-            if have_lsof
-                @test n_tcp == count_tcp()
             end
         end
     end