Comment 7 for bug 1285184

I think it is the Ubuntu font that causes the problem.

This works fine:
import QtQuick 2.0

Text {
    font.family: "Helvetica"
    width: 200
    height: 200
    maximumLineCount: 2
    text: "foo\nfoo"
}

This gives the problem:

import QtQuick 2.0
Text {
    font.family: "Ubuntu"
    width: 200
    height: 200
    maximumLineCount: 2
    text: "foo\nfoo"
}

Without specifying font.family, the problem is there because Ubuntu font is chosen by default (I don't know why, probably a system setting). When I uninstalled the ttf-ubuntu-font-family package, the app ran without the problem when not specifying font.family.