[Huawei Mate 9 Questions & Answers] Gynsu2000:
Ok, so now the phone is correctly starting but I have 2 issues.

First one is more an annoyance than an issue: when I reach the "About" screen, the model pf the phone is marked as ... "Unknown". I've tried to flash in fastboot the correct OEMINFO (using the file from there : https://xdaforums.com/mate-9/development/oeminfo-library-t3555353 ). After that the bootloader was locked and .... I still have an Unknow phone.

Second issue is that I've tried to install superSU but it doesn't seem to work.

Install output is the following:

sukernel v2.82 (ndk:arm64-v8a) - Copyright (C) 2014-2017 - Chainfire & CCMT

Loading from [/sutmp/ramdisk] ...

- System-less mode, boot image support required
- Creating paths
mkdir: can't create directory '/su/bin': File exists
mkdir: can't create directory '/su/xbin': File exists
I:[MTP] MtpServer::run fd: 18
E:[MTP] request read returned -1, errno: 22, exiting MtpServer::run loop
mkdir: can't create directory '/su/lib': File exists
mkdir: can't create directory '/su/etc': File exists
mkdir: can't create directory '/su/su.d': File exists
- Removing old files
- Placing files
rm: can't remove '/su/bin/su': No such file or directory
rm: can't remove '/su/bin/daemonsu': No such file or directory
rm: can't remove '/su/bin/supolicy_wrapped': No such file or directory
rm: can't remove '/su/lib/libsupol.so': No such file or directory
rm: can't remove '/su/bin/sukernel': No such file or directory
I:[MTP] MtpServer::run fd: 18
E:[MTP] request read returned -1, errno: 22, exiting MtpServer::run loop

******************
Boot image patcher
******************
- Finding boot image
--- Boot image: /dev/block/sdd35
- Extracting ramdisk
sukernel v2.82 (ndk:arm64-v8a) - Copyright (C) 2014-2017 - Chainfire & CCMT

Loading from [/dev/block/sdd35] ...

magic: [ANDROID!]
kernel: [12078158] (12079104) @ 0x00080000
ramdisk: [0] (0) @ 0x07c00000
second: [0] (0) @ 0x00f00000
tags: @ 0x07a00000
page size: 2048
unused: [0x00000000] [0x10000125]
dtb(?): [0] (0)
name: []
command line: [loglevel=4 initcall_debug=n page_tracker=on slub_min_objects=16 unmovable_isolate1=2:192M,3:224M,4:256M printktimer=0xfff0a000,0x534,0x538 androidboot.selinux=enforcing buildvariant=user]
extra command line: []
id: [0xe3bfe4262954c0437ae810fc16281a76152117bb000000000000000000000000]

Saving to [/sutmp/ramdisk.packed] ...

- Decompressing ramdisk (none)
- Checking patch status
sukernel v2.82 (ndk:arm64-v8a) - Copyright (C) 2014-2017 - Chainfire & CCMT

Loading from [/sutmp/ramdisk] ...

--- Already patched, attempting to find stock backup
sukernel v2.82 (ndk:arm64-v8a) - Copyright (C) 2014-2017 - Chainfire & CCMT

Loading from [/sutmp/ramdisk] ...

--- Stock restore failed, attempting ramdisk restore
sukernel v2.82 (ndk:arm64-v8a) - Copyright (C) 2014-2017 - Chainfire & CCMT

Loading from [/sutmp/ramdisk] ...

--- Ramdisk restore failed, aborting
umount: can't umount /su: Invalid argument
BusyBox v1.22.1 bionic (2018-01-13 12:03 +0100) multi-call binary.

Usage: losetup [-r] [-o OFS] {-f|LOOPDEV} FILE - associate loop devices
losetup -d LOOPDEV - disassociate
losetup -a - show status
losetup -f - show next free loop device

-o OFS Start OFS bytes into FILE
-r Read-only
-f Show/use next free loop device

I:[MTP] MtpServer::run fd: 18
E:[MTP] request read returned -1, errno: 22, exiting MtpServer::run loop
I:[MTP] MtpServer::run fd: 18
E:[MTP] request read returned -1, errno: 22, exiting MtpServer::run loop
I:[MTP] MtpServer::run fd: 18
E:[MTP] request read returned -1, errno: 22, exiting MtpServer::run loop
I:[MTP] MtpServer::run fd: 18
E:[MTP] request read returned -1, errno: 22, exiting MtpServer::run loop
I:[MTP] MtpServer::run fd: 18
E:[MTP] request read returned -1, errno: 22, exiting MtpServer::run loop
I:[MTP] MtpServer::run fd: 18
E:[MTP] request read returned -1, errno: 22, exiting MtpServer::run loop
- Unmounting /system and /vendor
- Done !
I:Updater process ended with RC=0
I:Install took 8 second(s).
I:[MTP] MtpServer::run fd: 18
E:[MTP] request read returned -1, errno: 22, exiting MtpServer::run loop
Updating partition details...
I:Data backup size is 1571MB, free: 51976MB.
I:Unable to mount '/usb-otg'
I:Actual block device: '', current file system: 'auto'
...done

Full log: https://pastebin.com/QGKdMEPU

I've tried 2 other versions but the result is the same.