various packages show as installed, but files are not present

I have seen this happen with libgtkmm as well. From what I can tell, it seems to happen when the installer fails to install grub at the end, and then I have to manually install grub to get the system to boot. Did this happen to you? Can you attach your /var/log/installer files?

I never imagined that it could be this.

On both Installs I used a custom setup in which I had my system directly on disk in a PV which means I had to manually install Grub using a patched Grub. I believe the installer does not allow to not install Grub, so I direct it at /dev/sda (for instance) and it will fail using the regular grub, of course.

I mean that the regular grub will fail. Then I install grub manually.

So yes, you are right on the money here. I have no installer log anymore (?). But I think it should be clear enough already :).

Well, perhaps not. But. Oh wait, it's on another /var.... Not there either. I will have to redo the install some time to find out. Other system.... Also nothing, I assume it gets wiped? Maybe it never gets created.

The regular Grub will produce this error message on my system:

/usr/sbin/grub-install: error: disk `lvmid/bn8p8J-Wr6M-Qzel-E0t8-8yOV-PbQN-TgKc6P/3Xl0mm-8loM-TcZ2-7pki-oF2S-MSEt-oBcPGT' not found.

Which is a bit weird, I thought it would bug out on /dev/sda. But anyway, regular patched grub will say:

Installation finished. No error reported.

That's currently a git version (from Savannah) but the same for the Supplied Ubuntu version. Anyway, that's irrelevant.

I indeed have a failing grub at install ;-). Regards.

It happened again on an install of 16.04.3.

Ubiquity leaves behind no installer log on the installed system so again I do not have any sorry.

I would have to reinstall somewhere sometime and ensure that grub fails. In principle that's easy enough.

Here is the list of packages that have incomplete files:

btrfs-tools
casper
cifs-utils
dmraid
fcitx-frontend-all
fcitx-frontend-gtk2
fcitx-frontend-gtk3
fcitx-frontend-qt4
fcitx-frontend-qt5
fcitx-module-cloudpinyin
fcitx-module-dbus
fcitx-module-kimpanel
fcitx-module-lua
fcitx-module-x11
fcitx-pinyin
fcitx-table
fcitx-ui-classic
jfsutils
kde-config-fcitx
kpartx
kpartx-boot
libdmraid1.0.0.rc16
libfcitx-gclient0
libfcitx-qt0
libfcitx-qt5-1
libgeoclue0
libjavascriptcoregtk-4.0-18
liblua5.2-0
libwebkit2gtk-4.0-37
libwebkit2gtk-4.0-37-gtk2
linux-image-4.10.0-28-generic
linux-signed-generic-hwe-16.04
linux-signed-image-4.10.0-28-generic
linux-signed-image-generic-hwe-16.04
lupin-casper
mokutil
presage
python3-cupshelpers
reiserfsprogs
ubiquity-slideshow-kubuntu
user-setup
xfsprogs
zenity
zenity-common

As you can see many of these (or most of these) would get removed after install. So the problem is more that this package removal doesn't happen.