Today because of an update conflict with Nvidia I decided to remove nvidia-lts and install nvidia-dkms. Pamac duly did this and the update conflict disappeared. On a reboot no desktop. it appears nvidia-dkms needs linux-lts-headers which were not installed.
I feel the linux-lts-headers should be a dependency of nvidia-dkms
Just checked and there are two optional header packages but optional doesn't help if it breaks the desktop.
I only use pamac for an alert that there are upgrades available and to browse packages.
As I have had problems with it that may be related to openbox-lxpolkit and not pamac itself, I
learned within hours to use yaourt and yaourt-gui (tui) which works great with main and aur pkgs.
Yaourt asks for root and user passwords to install and compile pkgs from aur which seems
that pamac on LX does not have the right configuration to do it runs in either user or as root.
What I really miss is the xfce-looking Manja-settings for kernel browsing and upgrades.
I will correct myself, by mistake I had removed lxpolkit from autostart, pamac works fine in openbox/LXDE as long as lxpolkit is running