can't change access mode of IO object with zeus

[teaforthecat]

io.optimize_image( dragonfly_file.tempfile )

.bundle/ruby/1.9.1/gems/image_optim-0.6.0/lib/image_optim/worker.rb:66:in `reopen': /dev/pts/6 can't change access mode from "r+" to "w" (ArgumentError)

using ruby 1.9.3 on ubuntu 12.04
using dragonfly
trying to follow this gist: https://gist.github.com/3320781
but running in rails console also does not work.
Not sure where to start looking into this error. help?

[teaforthecat]

I'm not sure why /dev/null (or /dev/pts/6 in the error above) are set to read-only for me. Not changing the mode of that IO object fixes the issue.
I'm not sure if this would be the best option, but it is working for me:
teaforthecat@0e95693

[teaforthecat]

Ah Ha!
I am using zeus, which redirects io. so that is why /dev/pts/6 is readonly.
Is this something you want to address @toy?

[toy]

Seems you have already found source of problem :)
I think I need to simplify way of starting process, it is simple to change way of redirecting stdout and stderr (2>&1 >/dev/null), changing priority can be done using nice command (which as I understand should be present on all posix system), setting environment variable should be also simple.