Here is the tip, if somebody has the same issue (waiting for recovery mode) :

Phone on "recovery mode".

Terminal :
sudo adb devices

If ‘no permission’ :
sudo adb kill-server
sudo adb start-server

@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.

@hummlbach No, even with the latest installer (*.21) it didn't work. The installer couldnt debug my recovery mode.

But i read several posts about the Mx4 and this phone seems a bit specific (many versions ?).
And i read several posts of people having the same problem as i had.

At least i hope this can help some people, or maybe help to improve the installer.

Here is the tip, if somebody has the same issue (waiting for recovery mode) :

Phone on "recovery mode".

Terminal :
sudo adb devices

If ‘no permission’ :
sudo adb kill-server
sudo adb start-server

@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.

Thanks for your time.

Once again, whatever i do, all commands made by terminal on my labtop finish with :
"2018/08/20 19:05:37 Can't flash recovery image"

Sooooo frustrating.

Edit - I follow with interest this conversation about installing UBports without cable but with terminal and then i realise that on my all-new Ubuntu touch legacy installation, i dont have access to the ubuntu store and then i have no terminal...

Well, no luck this afternoon.

I flashed 3 differents recovery.img for Arale found on the web, with none i could access to a functionnal recovery mode.

I tried to push files with fastboot mode, every time it ends with "image is not a boot image", 15.04 or 16.04, the same.

To try different recovery : sudo fastboot flash recovery recovery.img
Phone verified with : adb devices
I tried:
sudo ubuntu-device-flash --server https://system-image.ubports.com touch --channel ubports-touch/15.04/stable --bootstrap
sudo ubuntu-device-flash --server=https://system-image.ubports.com touch --device=arale --channel=ubports-touch/16.04/rc --bootstrap --wipe
sudo ubuntu-device-flash --server=http://system-image.ubports.com touch --device=arale --channel=15.04/stable --wipe

Well, im stucked... So frustrating !

Ok, thx for your time, i report back.

1. When i copy/paste your last command line, i got the response :
   invalid argument for flag `--revision' (expected int): strconv.ParseInt: parsing "version-9": invalid syntax

2. I tried without the "--revision=version-9". I got this :
   sudo ubuntu-device-flash --server=https://system-image.ubports.com touch --device=arale --channel=ubports-touch/16.04/rc --bootstrap --wipe
   2018/08/20 12:25:59 Device is |arale|
   2018/08/20 12:26:00 Flashing version 9 from ubports-touch/16.04/rc channel and server https://system-image.ubports.com to device arale
   376.66 MB / 376.66 MB [====================================] 100.00 % 1.70 MB/s
   /home/slayne/.cache/ubuntuimages/pool/keyring-4c4e7ef380ebcfa2c31084efa199138e93bfed8fc58aa3eb06bdf75a78af9b57.tar.xz
   /home/slayne/.cache/ubuntuimages/pool/device-c746103f205781974a7b89aff29cdf3dd450879f119f672d3a6f62b67ed783c5.tar.xz
   2018/08/20 12:29:55 Can't flash recovery image

I went pretty well until the last line !
On the phone on recovery mode, i read "image is not a boot image".

We're getting close, i hope.

Thats what i got :

slayne@slayne-PcAsus:~$ sudo ubuntu-device-flash --server=http://system-image.ubports.com touch --device=arale --channel=15.04/stable --revision=version_3
invalid argument for flag `--revision' (expected int): strconv.ParseInt: parsing "version_3": invalid syntax

I tried without the 'revision' :

slayne@slayne-PcAsus:~$ sudo ubuntu-device-flash --server=http://system-image.ubports.com touch --device=arale --channel=15.04/stable
2018/08/20 09:23:39 Device is |arale|
2018/08/20 09:23:39 Flashing version 3 from 15.04/stable channel and server http://system-image.ubports.com to device arale
2018/08/20 09:23:39 Cannot cleanup tree to ensure clean deploymentexit status 1

Hope that helps.

Thanks.

I looked a bit around, and if recovery mode seems broken, fastboot mode works perferctly.

I found an old topic with another way to install ubports : this one

This command line seems interesting :
sudo ubuntu-device-flash --server=http://system-image.ubports.com touch --device=arale --channel=15.04/stable --bootstrap --wipe

But i cant find any recovery image from ubports for device mx4 arale (all links are dead, although its only 6 months old).
If anydoby has a link for a recovery img, i'll take it !

Thx for the tip.
I tried with the oldest installer, but its still the same issue.

Then i reinstalled Ubuntu touch with Sp flash tools, tried again, and still unable to enter recovery mode.

Is it a known bug ?
Is there another way to install Ubports Ubuntu touch ? An image i could flash with Sp flash tools ?

Hi everybody,

I own a Meizu mx4 that i long time ago flashed with Android (when Ubuntu touch was abandonned), but its the 'ubuntu edition'.

I now want to switch it back to Ubuntu.

I followed the guide this one to flash Ubuntu touch 'legacy' on it, and it works perfectly.
But now, im stuck with it.

I run Ubports Installer last version (0.1.21) on Ubuntu 18.04.
My device is recognized by the installer, but its stucked on "waiting device to enter recovery mode'.
The phone is blocked on the ubuntu screen, and the 'black bar' doesnt move at all. See the picture.

When i try to enter recovery mode without the Ubports installer, its the same (stucked at this screen).
I tried on another PC, with another usb cable. Same.

If you have any idea, thanks !