Comment 1 for bug 518138

I do understand well the problem :
What do you mean by 'I press the play buttons the image disappears from the preview window' . which images ? From live capture , from capture area , from montage area ?

I did not success to reproduce the problem.
But effectively when you press play button, the live acquisition is stopped. The images in montage area is played ( supposed to) . Then the luciole logo appears

Now to have output form command line , you have 2 commands :
 - luciole -v who display Debug messages in CLI or
 - luciole - who logs debug message in a file located in $USER/.luciole/luciole.log