@advocatux It doesnt work.
But is doesnt matter because I UPGRADED MY MX4 TO UBPORTS !!! Finally !
As i thought, the main problem was the buggy recovery mode.
I tried :
sudo adb devices
75HABLM26VFN no permissions (verify udev rules); see [http://developer.android.com/tools/device.html]
(note : all these commands were made while phone on "recovery mode")
This "no permissions" was the key.
Then i did :
slayne@slayne-PcAsus:~$ sudo adb kill-server
slayne@slayne-PcAsus:~$ sudo adb start-server
- daemon not running. starting it now on port 5037 *
- daemon started successfully *
slayne@slayne-PcAsus:~$ adb devices
List of devices attached
75HABLM26VFN recovery
That "recovery" instead of "no permissions" seemed pretty good.
I retried one of the last commands i did yesterday :
slayne@slayne-PcAsus:~$ sudo ubuntu-device-flash --server=https://system-image.ubports.com touch --device=arale --channel=ubports-touch/16.04/rc
2018/08/21 09:56:51 Device is |arale|
2018/08/21 09:56:51 Flashing version 9 from ubports-touch/16.04/rc channel and server https://system-image.ubports.com to device arale
2018/08/21 09:56:52 Start pushing /home/slayne/.cache/ubuntuimages/pool/keyring-4c4e7ef380ebcfa2c31084efa199138e93bfed8fc58aa3eb06bdf75a78af9b57.tar.xz to device
2018/08/21 09:56:52 Start pushing /home/slayne/.cache/ubuntuimages/ubports-touch/16.04/rc/arale/version-9.tar.xz to device
2018/08/21 09:56:52 Done pushing /home/slayne/.cache/ubuntuimages/pool/keyring-4c4e7ef380ebcfa2c31084efa199138e93bfed8fc58aa3eb06bdf75a78af9b57.tar.xz to device
2018/08/21 09:56:52 Start pushing /home/slayne/.cache/ubuntuimages/gpg/image-master.tar.xz to device
2018/08/21 09:56:52 Done pushing /home/slayne/.cache/ubuntuimages/ubports-touch/16.04/rc/arale/version-9.tar.xz to device
2018/08/21 09:56:52 Start pushing /home/slayne/.cache/ubuntuimages/gpg/image-signing.tar.xz to device
2018/08/21 09:56:52 Done pushing /home/slayne/.cache/ubuntuimages/gpg/image-master.tar.xz to device
2018/08/21 09:56:52 Done pushing /home/slayne/.cache/ubuntuimages/gpg/image-signing.tar.xz to device
2018/08/21 09:57:03 Start pushing /home/slayne/.cache/ubuntuimages/pool/device-c746103f205781974a7b89aff29cdf3dd450879f119f672d3a6f62b67ed783c5.tar.xz to device
2018/08/21 09:57:03 Start pushing /home/slayne/.cache/ubuntuimages/pool/ubports-dfcbe0416dc5dddaa398eff83a60d883c0d693dd1b1958e2fd9b61a02771e4ee.tar.xz to device
2018/08/21 09:57:35 Done pushing /home/slayne/.cache/ubuntuimages/pool/device-c746103f205781974a7b89aff29cdf3dd450879f119f672d3a6f62b67ed783c5.tar.xz to device
2018/08/21 09:59:27 Done pushing /home/slayne/.cache/ubuntuimages/pool/ubports-dfcbe0416dc5dddaa398eff83a60d883c0d693dd1b1958e2fd9b61a02771e4ee.tar.xz to device
2018/08/21 09:59:27 Created ubuntu_command: /home/slayne/.cache/ubuntuimages/ubuntu_commands324087129
2018/08/21 09:59:27 Rebooting into recovery to flash
AND IT WORKED !!
Thanks everydoby for your time and your help. Now im in.