libubox Interrupted system call

test-uloop.lua

#!/usr/bin/env lua

-- the following will eventually fail on lua5.1 and luajit
-- with:
-- 	lua: test-uloop.lua:30: Interrupted system call

uloop = require 'uloop'
uloop.init()

local t

function t__()
	t:set(1)
end

t = uloop.timer(t__, 1)

uloop.timer(function()
	while true do
		print('popen test')
		local i = io.popen('ifconfig', 'r')
		for line in i:lines() do
			print(line)
		end
	end
end, 1)

uloop.run()

I'm seeing this too, but this seems to be more of a popen/read problem than a uloop problem: the read() in lines() receives 2 SIGCHLDs as 'ifconfig' and its parent shell complete and fails to restart the read.