@Ingo I'm trying to update lxc-android-config which is part of UT and is failing. After I installed OTA 11 there were more than 130 updates and only lxc-android-config fails. This is clean OTA-11 on nexus5 I'm not installing anything additional just updating.

@Ingo simple update

phablet@ubuntu-phablet:~$ sudo apt update
Hit:1 http://ports.ubuntu.com/ubuntu-ports xenial InRelease
Get:2 http://ports.ubuntu.com/ubuntu-ports xenial-updates InRelease [109 kB]
Ign:3 http://repo.ubports.com xenial InRelease                                 
Get:4 http://ports.ubuntu.com/ubuntu-ports xenial-security InRelease [109 kB]
Hit:5 http://repo.ubports.com xenial Release                                  
Fetched 218 kB in 1s (164 kB/s)                   
Reading package lists... Done
Building dependency tree       
Reading state information... Done
1 package can be upgraded. Run 'apt list --upgradable' to see it.
W: No sandbox user '_apt' on the system, can not drop privileges
phablet@ubuntu-phablet:~$ sudo apt upgrade 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
  abootimg android-tools-adbd bridge-utils cameraplugin-aal
  gstreamer1.0-hybris hybris-usb initramfs-tools-ubuntu-touch
  libboost-locale1.58.0 libboost-serialization1.58.0 libertine-scope
  libhybris-test libllvm3.8 liblxc1 libmircommon6 libmirplatform13
  libmirserver41 libsodium18 libunity-scopes1.0 libzmq5 libzmqpp4 lxc
  lxc-android-config lxc-common lxc1 mir-client-platform-android-caf5
  mir-client-platform-android5 mir-graphics-drivers-android
  mir-graphics-drivers-android-caf mir-platform-graphics-android-caf10
  mir-platform-graphics-android-caf15 mir-platform-graphics-android10
  mir-platform-graphics-android15 mir-platform-input-evdev5
  mir-platform-input-evdev7 ocl-icd-libopencl1 pulseaudio-module-droid
  pulseaudio-modules-droid-24 pulseaudio-modules-droid-glue-24 python3-lxc
  qml-module-qt-labs-platform qtubuntu-android rsync
  ubuntu-touch-generic-initrd unity-plugin-scopes unity-scope-click
  unity-scope-click-departmentsdb unity-scope-scopes
Use 'sudo apt autoremove' to remove them.
The following packages will be upgraded:
  lxc-android-config
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/45.2 kB of archives.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] y
(Reading database ... 51193 files and directories currently installed.)
Preparing to unpack .../lxc-android-config_0.232+ubports0+0~20191030222838.24~1.
gbp51f311_all.deb ...
Unpacking lxc-android-config (0.232+ubports0+0~20191030222838.24~1.gbp51f311) ov
er (0.232+ubports0+0~20190703214209.23~1.gbp5981e2) ...
dpkg: error processing archive /var/cache/apt/archives/lxc-android-config_0.232+
ubports0+0~20191030222838.24~1.gbp51f311_all.deb (--unpack):
 unable to make backup link of './lib/udev/rules.d/70-android.rules' before inst
alling new version: Invalid cross-device link
Processing triggers for dbus (1.10.6-1ubuntu3.4) ...
Processing triggers for ureadahead (0.100.0-19.1) ...
Errors were encountered while processing:
 /var/cache/apt/archives/lxc-android-config_0.232+ubports0+0~20191030222838.24~1
.gbp51f311_all.deb
W: No sandbox user '_apt' on the system, can not drop privileges
E: Sub-process /usr/bin/dpkg returned an error code (1)
phablet@ubuntu-phablet:~$ 

any ideas ?

Get:1 http://repo.ubports.com xenial/main armhf lxc-android-config all 0.232+ubports0+0~20191030222838.24~1.gbp51f311 [45.2 kB]
Fetched 45.2 kB in 0s (95.0 kB/s)       
(Reading database ... 51193 files and directories currently installed.)
Preparing to unpack .../lxc-android-config_0.232+ubports0+0~20191030222838.24~1.
gbp51f311_all.deb ...
Unpacking lxc-android-config (0.232+ubports0+0~20191030222838.24~1.gbp51f311) ov
er (0.232+ubports0+0~20190703214209.23~1.gbp5981e2) ...
dpkg: error processing archive /var/cache/apt/archives/lxc-android-config_0.232+
ubports0+0~20191030222838.24~1.gbp51f311_all.deb (--unpack):
 unable to make backup link of './lib/udev/rules.d/70-android.rules' before inst
alling new version: Invalid cross-device link
Processing triggers for dbus (1.10.6-1ubuntu3.4) ...
Processing triggers for ureadahead (0.100.0-19.1) ...
Errors were encountered while processing:
 /var/cache/apt/archives/lxc-android-config_0.232+ubports0+0~20191030222838.24~1
.gbp51f311_all.deb
W: No sandbox user '_apt' on the system, can not drop privileges
E: Sub-process /usr/bin/dpkg returned an error code (1)

Same here (Nexus 5) it seems is a pulseaudio issue, can't switch profile to headset_head_unit when trying to use bluetooth headset/car kit microphone

profiles:
		a2dp_sink: High Fidelity Playback (A2DP Sink) (priority 10, available: unknown)
		headset_head_unit: Headset Head Unit (HSP/HFP) (priority 20, available: unknown)
		off: Off (priority 0, available: yes)
	active profile: off

I manage to force it to switch to A2DP but of course no mic

profiles:
		a2dp_sink: High Fidelity Playback (A2DP Sink) (priority 10, available: unknown)
		headset_head_unit: Headset Head Unit (HSP/HFP) (priority 20, available: unknown)
		off: Off (priority 0, available: yes)
	active profile: <a2dp_sink>