nobu / ruby-lang.org wrote: > After requiring 'io/nonblock', no needs to see if `nonblock=` method is available. Doesn't that raise NotImplementedError on some platforms? I see this in ext/io/nonblock/nonblock.c: #define rb_io_nonblock_set rb_f_notimplement I'm not sure which platforms, though, maybe Windows? > And `IO#close_on_exec=` is older than `IO#nonblock=`. I remember using IO#nonblock= in 1.8 (was pure Ruby, then), but not IO#close_on_exec=