Summary, the Ubuntu team plans to remove the synaptic driver on upgrades since it confuses GNOME, that might have an impact on Unity users though since unity-control-center doesn’t know how to configure libinput
The plan is to have the dist-upgrader removing xserver-xorg-input-synaptics and not use Conflicts, that way users who need it can install the old driver back (that could include Unity users, though at the cost of creating issue for GNOME sessions) and nobody is going to uninstall GNOME by mistake.
Ideally the Unity team would update unity-control-center to be able to configure libinput (the topic might be on topic for the Unity subsection of the forum but it seems one needs special permissions to post there).
Next cycle we are probably going to look at removing xserver-xorg-input-synaptics from the archive since libinput should be then good enough for everyone by the next LTS and the recommended solution.
Doing it this year may be premature. It’s not just assuming we’ve fixed everyone’s libinput concerns, but also unnecessary. xserver-xorg-input-synaptics is a mature package that works very well. Some people will want to keep using it, and I use it regularly right now in helping people to debug touchpad issues. But sure, if that stopped being so in future then we could talk about removing it. I don’t think we should be talking about removing it yet.
Well, post LTS is the good time to try new things a bit harder, if it turns out to not work out for some reasons we can sort it out and look for a plan B (bringing back synaptic for example).
Anyway that’s not for this cycle and open for discussion so if you have strongs reasons you think libinput isn’t going to work for you maybe let’s discuss them and file bug reports so we can see if we can address the issues and move forward on that topic?
If dist-upgrader removes xserver-xorg-input-synaptics while user using unity how that will work? Removing synaptics mean mouse will stop working.
This issue is more complicated than that. Gnome-control-center should try to detect if synaptics is installed (see bug). This was fixed in the bug report. Is it not?
I am ok with removing it from seed though. For unity we already have ubuntu-unity-desktop on universe. I can add synaptics to seed or I will make u-c-c depends on xserver-xorg-input-synaptics
Unity-control-center can be ported to libinput. But then unity will lose some well established functionality. Synaptics works very well for some and has some advanced mechanism which libinput lacks. I am going to file a bug with details.
No, gnome-control-center doesn’t handle the synaptics driver and doesn’t even warn if it’s in use. But if is installed, the mouse and touchpad settings will not work properly in GNOME.
One complication is that Unity is not automatically removed on upgrades. Therefore, unity and unity-control-center can’t depend on xserver-xorg-input-synaptics for 18.04 LTS without causing problems for people upgrading. And since Unity still won’t be automatically removed in 18.10 and beyond either, several Ubuntu Desktop Team members are proposing to completely remove the synaptics driver in 18.10 to fully solve this problem. That depends on Unity and Xubuntu handling libinput instead though.
No the mouse does not stop working in Unity. If you remove xserver-xorg-input-synaptics then you still have xserver-xorg-input-libinput, which works. The only loss of functionality is that unity-control-centre (System Settings > Mouse & Touchpad) can’t configure it.
That code is not what we want. It just does: g_warning ("Detected synaptics X driver, please migrate to libinput");
which means it only appears in the log and normal users won’t see it. It’s also not a sufficiently user-friendly message to put in the GUI. We will need something more informative.