read just one line when checking md5
read just one line when checking md5

in some cases reading the whole file fails (on macOS High Sierra, LuaJIT)
this is timing dependent and waiting between spawning and reading solves the issue as well
luarocks/luarocks,luarocks/luarocks,keplerproject/luarocks,keplerproject/luarocks,luarocks/luarocks,tarantool/luarocks,tarantool/luarocks,keplerproject/luarocks,keplerproject/luarocks,tarantool/luarocks