[ebuild     UD] dev-qt/qtgui-5.7.1-r1 [5.9.2] USE="dbus egl* gif gtk%* jpeg libinput png udev xcb -accessibility -debug -eglfs -evdev (-gles2) -ibus {-test} -tslib -tuio (-vnc%)" 

!!! Multiple package instances within a single package slot have been pulled
!!! into the dependency graph, resulting in a slot conflict:

dev-qt/qtgui:5

  (dev-qt/qtgui-5.7.1-r1:5/5.7::gentoo, ebuild scheduled for merge) pulled in by
    =dev-qt/qtgui-5.7.1-r1::gentoo (Argument)

  (dev-qt/qtgui-5.9.2:5/5.9::gentoo, installed) pulled in by
    ~dev-qt/qtgui-5.9.2[dbus] required by (dev-qt/qtwidgets-5.9.2:5/5.9::gentoo, installed)
    ^             ^^^^^                                                                     
    (and 1 more with the same problem)

NOTE: Use the '--verbose-conflicts' option to display parents omitted above