get nested tmux screen log

What happen: pipe-pane sub-command get wrong log while tmux run in nested

Before this, I used the following method to grab the screen log of the tmux dettach session and it has been working well:

session=console-$vmname
tmux new -s $session -d vm console $vmname \; pipe-pane "cat >$logpath/console-$vmname.log"

But when I tried to run the test script in tmux instead in normal terminal, I found that the virsh console log is not expected. The captured log from pipe-pane becomes the standard output of the script itself instead the real VM console log.

workaround or resolution

After many tests and confirmations, we first eliminated the bug in bash itself; the problem should be caused by the default behavior of tmux pipe-pane itself. Then I checked the tmux man page and found that the pipe-pane command has a -t option, which can be used to specify a target pane; then after searching and tring I found that the pane name/ID corresponding to a single session is ${session}:0.0. So the final solution is:

session=console-$vmname
tmux new -s $session -d vm console $vmname \; pipe-pane -t ${session}:0.0 "cat >$logpath/console-$vmname.log"