Expect: interact with a pipeline

[Sébastien Mazy]

Hello,

I'm struggling with the following chunk of code:

# pipeline_interact.exp
set channel [open {|tee out.log} RDWR]
fconfigure $channel -buffering none
spawn -noecho -open $channel
interact

which I expect to work like:

# normal_interact.exp
spawn -noecho tee out.log
interact

Instead, out.log remains empty whatever I type (including carriage
return), and nothing is echoed back. "expect" and "send" work in both
cases though.

Could anybody please shed some light on what I did wrong?

Sébastien