I have a Nexus 4 with Android 4.3 installed and I want to flash it to Ubuntu Touch. My system is Ubuntu 12.04, running inside a virtual machine on Mac OS 10.5.8. To use the VM, I opened an NAT bridge and forwarded port 5037 for adb, I can see the Nexus with adb and e.g. use the adb shell into it. USB ports are also forwarded to the VM.

I follow these instructions to the letter. My bootloader is unlocked, just as it was described in the instructions. Now I encounter different issues, when executing sudo phablet-flash ubuntu-system --no-backup.

On the first run, it got stuck in this state:

INFO:phablet-flash:Decompressing partitions/recovery.img from /home/till/Downloads/phablet-flash/imageupdates/pool/device-5ba3031cb0d6fc624848266edba781e3e821b6e1e8dd21105725f0ab26077d0a.tar.xz
INFO:phablet-flash:Restarting device... wait
INFO:phablet-flash:Restarting device... wait complete
INFO:phablet-flash:Booting /tmp/tmpMSN8bm/partitions/recovery.img
< waiting for device >
downloading 'boot.img'...
OKAY [  1.772s]
booting...
OKAY [  0.005s]
finished. total time: 1.779s
INFO:phablet-flash:Waiting for recovery image to boot

The following happened: around the line "INFO:phablet-flash: Restarting...", it rebooted into the bootloader. The bootloader shows only for two seconds, then the screen goes off and the phone stays off. But I do notice, that the screen is not off - it is just black, but the background light is on. If I wait long enough, phablet-flash aborts with ERROR:phablet-flash:Wait for recovery expired

On the second try, I wanted to manually start the bootloader and choose "Recovery mode". Pressing "volume down+power" at first did nothing. Releasing the buttons and then pressing them again brought me into the bootloder. After choosing "Recovery mode", phablet-flash continued and after a while aborted with the following output:

INFO:phablet-flash:Wait for recovery image to boot complete
INFO:phablet-flash:Clearing /data and /cache
INFO:phablet-flash:Pushing /home/till/Downloads/phablet-flash/imageupdates/pool/ubuntu-2b5345658b58e55207c4a4e7b6b3d8cd4f3d9a3187d2448fc9020c884234bac0.tar.xz to /cache/recovery/
failed to copy '/home/till/Downloads/phablet-flash/imageupdates/pool/ubuntu-2b5345658b58e55207c4a4e7b6b3d8cd4f3d9a3187d2448fc9020c884234bac0.tar.xz' to '/cache/recovery/': Permission denied
ERROR:phablet-flash:Command 'adb push /home/till/Downloads/phablet-flash/imageupdates/pool/ubuntu-2b5345658b58e55207c4a4e7b6b3d8cd4f3d9a3187d2448fc9020c884234bac0.tar.xz /cache/recovery/' returned non-zero exit status 1
Removing directory /tmp/tmpDnbz6N
Removing directory /tmp/tmpth4L6w

What can I do to properly flash my phone with Ubuntu Touch? I noticed that adb does not show the phone in recovery mode: Typing adb devices, when the Nexus 4 is in recovery mode, shows the serial number and the state device, where it should show recovery.

Should the phone be rooted? This is not mentioned in the instructions.