[ROM][11] LineageOS 18.0 [UNOFFICIAL]

[Olivier]

LineageOS is a free, community built, aftermarket firmware distribution of Android 10, which is designed to increase performance and reliability over stock Android for your device.

/*
* Your warranty is now void.
*
* I am not responsible for bricked devices, dead SD cards,
* thermonuclear war, or you getting fired because the alarm app failed. Please
* do some research if you have any concerns about features included in this ROM
* before flashing it! YOU are choosing to make these modifications, and if
* you point the finger at me for messing up your device, I will laugh at you.
*/

NOTE
Should you ever face any issues, capture logs. I also need to know what build you're on (build number or at least a date).
Hint: "It doesn't work" is not a bug report and posts like this will be ignored.


KNOWN ISSUEs

• SELinux is set to permissive
• The Sony stock camera does not work at the moment.
• Of course, there may be many other bugs I'm not aware of, so please do NOT upgrade from 17.1 unless you know what you're doing and/or want to run experimental builds.

INFO
This ROM does not use the device trees/kernel from sonyxperiadev (aka SODP). The device tree was made from scratch, and the stock kernel (based off 52.1.A.x.y) has been used.

DOWNLOAD
All unofficial builds

INSTRUCTIONS
First install
Updating to a newer build
Just flash the builds as usual. Make sure to be on the latest stock firmware.

SOURCE
LineageOS
Kernel


XDA:DevDB Information
Lineage 18.0 for the Sony Xperia XZ2 Compact, ROM for the Sony Xperia XZ2 Compact

Contributors
Olivier, Sjll
Source Code: https://github.com/LineageOS

ROM OS Version: 2.3.x Gingerbread
ROM Kernel: Linux 4.x
ROM Firmware Required: 52.1.A.3.49

Version Information
Status: Beta

Created 2020-11-27
Last Updated 2020-11-27

 

[Olivier]

Changelog

CHANGELOG
20201128:
- fixed NFC

20201127:
- initial public release.

 

[landsome]

Thanks a lot. Great to know you are working on LOS18.

I tried sideloading with the latest LOS17.1 recovery (and LOS 17.1 on the phone, naturally). I get an error. Do I absolutely have to be on stock?

 

[patroj]

Are you still working on this one?

 

[Garfield24]

I am trying to flash a LOS image onto a single SIM Phone, but it always fails with error "unknown fuse request opcode 2016" in the recovery.log, and the system image is empty after the flash.

I am using the latest STOCK TWRP 2020-06-14_21-07-37_twrp_apollo.tar.gz.

It fails on all LOS images I have tried, 18.0 17.1 etc. So far I haven't been able to flash a LOS image at all successfully.

The flash performs normally, but fails with an error after 2-3 minutes, and afterwards the system partition is empty.

The unit is a SONY XZ2 Compact Single SIM.

After discussion with someone, this maybe due to the LOS image having an incorrect System partition size(?). Why does it flash correctly on most people's units, but not on this one?

Anyone has an idea? I am attaching the twrp.log files.

 

[lba810701]

I am trying to flash a LOS image onto a single SIM Phone, but it always fails with error "unknown fuse request opcode 2016" in the recovery.log, and the system image is empty after the flash.

I am using the latest STOCK TWRP 2020-06-14_21-07-37_twrp_apollo.tar.gz.

It fails on all LOS images I have tried, 18.0 17.1 etc. So far I haven't been able to flash a LOS image at all successfully.

The flash performs normally, but fails with an error after 2-3 minutes, and afterwards the system partition is empty.

The unit is a SONY XZ2 Compact Single SIM.

After discussion with someone, this maybe due to the LOS image having an incorrect System partition size(?). Why does it flash correctly on most people's units, but not on this one?

Anyone has an idea? I am attaching the twrp.log files.

Hi!
I'got the same situation, with a bad downloaded los.zip file. Maybe it's the problem.
But what i saw in your description, the used twrp. If i known good, for Android 11 the working twrp for coming from stock to los is here what works for me ( apollo ):

" https://androidfilehost.com/?w=files&flid=318609 " ;

And don't flash it to the recovery or boot partitiom, just temperoraly boot it with fastboot.

 

[Garfield24]

Hi!
I'got the same situation, with a bad downloaded los.zip file. Maybe it's the problem.
But what i saw in your description, the used twrp. If i known good, for Android 11 the working twrp for coming from stock to los is here what works for me ( apollo ):

" https://androidfilehost.com/?w=files&flid=318609 " ;

And don't flash it to the recovery or boot partitiom, just temperoraly boot it with fastboot.

Nope, not working.

I flashed a stock image with newflasher and booted to the apps. Original image boots fine.

Then I rebooted into fastboot and did: fastboot boot twrp.img like you suggested.

TWRP runs fine, I wipe the partitions, and flash LOS. No operating system installed afterwards.

I don't think it's a corrupt .zip file, since I tried about 5 different ones.

When flashing I get a message: "Unable to find partition for path /cache" in red colour.

Anyone knows what that means?

 

[lba810701]

Nope, not working.

I flashed a stock image with newflasher and booted to the apps. Original image boots fine.

Then I rebooted into fastboot and did: fastboot boot twrp.img like you suggested.

TWRP runs fine, I wipe the partitions, and flash LOS. No operating system installed afterwards.

I don't think it's a corrupt .zip file, since I tried about 5 different ones.

When flashing I get a message: "Unable to find partition for path /cache" in red colour.

Anyone knows what that means?

H

Nope, not working.

I flashed a stock image with newflasher and booted to the apps. Original image boots fine.

Then I rebooted into fastboot and did: fastboot boot twrp.img like you suggested.

TWRP runs fine, I wipe the partitions, and flash LOS. No operating system installed afterwards.

I don't think it's a corrupt .zip file, since I tried about 5 different ones.

When flashing I get a message: "Unable to find partition for path /cache" in red colour.

Anyone knows what that means?

Do you disabled the verified boot before rhe whole twrp process?

" fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img "

 

[Garfield24]

H

Do you disabled the verified boot before the whole twrp process?

" fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img "

Yes, I have tried that, too, just now again. As before, not working. I have tried so many things by now. The flash of the LOS image completes, but in step 2/2 I get "Unable to find partition for path /cache" , and it says completed. In the recovery log, there is an error "unknown fuse request opcode 2016" . The system partition is empty after the flash (7MB used).

I wonder, if there is a difference in the partitions on this specific phone. I am attaching the output of the following command:

cat /proc/partitions > /external_sd/partlog.txt

It writes an overview of partitions and their sizes to a file on the SD Card. There are 74 partitions on /sda. I wonder why anybody needs 74 partitions?

Can someone run the same command on their phone with a working and installed LOS and compare it to my file, if there is any difference to a phone that is working (partitions-sizes/-ordering?)?

I run the command from TWRP. Start up recovery TWRP and go to Advanced -> Terminal. There you can run the command.

cat /proc/partitions > /external_sd/partlog.txt

I would appreciate if someone could run that command on a phone where the LOS image works, and compare the file to my file, if there are any differences in the partitioning scheme or sizes. Sizes are important.

Any other suggestions also welcome.

 

[lba810701]

Yes, I have tried that, too, just now again. As before, not working. I have tried so many things by now. The flash of the LOS image completes, but in step 2/2 I get "Unable to find partition for path /cache" , and it says completed. In the recovery log, there is an error "unknown fuse request opcode 2016" . The system partition is empty after the flash (7MB used).

I wonder, if there is a difference in the partitions on this specific phone. I am attaching the output of the following command:

cat /proc/partitions > /external_sd/partlog.txt

It writes an overview of partitions and their sizes to a file on the SD Card. There are 74 partitions on /sda. I wonder why anybody needs 74 partitions?

Can someone run the same command on their phone with a working and installed LOS and compare it to my file, if there is any difference to a phone that is working (partitions-sizes/-ordering?)?

I run the command from TWRP. Start up recovery TWRP and go to Advanced -> Terminal. There you can run the command.

cat /proc/partitions > /external_sd/partlog.txt

I would appreciate if someone could run that command on a phone where the LOS image works, and compare the file to my file, if there are any differences in the partitioning scheme or sizes. Sizes are important.

Any other suggestions also welcome.

I attached it, but I'm on 17.1. Maybe help? But first round, it's seems the same except the last two line of the logs... In yours, there are "mcblk0" and "mmcblk0p1" what's missing from mine, but I haven't got sdcard so, maybe thats why.

 

[Garfield24]

I attached it, but I'm on 17.1. Maybe help? But first round, it's seems the same except the last two line of the logs... In yours, there are "mcblk0" and "mmcblk0p1" what's missing from mine, but I haven't got sdcard so, maybe thats why.

Yes, that definitely helps. Thank you. The last two lines is the SDCard, that's correct.

That means my phone has the same ROM size and partition size than yours, so the System partition is the same size.

I find an additional partition in your file in line 19:

254 0 1048576 zram0

I don't have a zram0 partition in my file and my phone.

The question now is: does that make any difference? Can that missing partition on my phone can cause the flash to fail?

 

[Garfield24]

After a LOT of trial and error I am making a description, how to get a running LOS on your SONY XZ2 Compact Single SIM (and probably Dual SIM). This is not a description for people, who got it running the easy way. It's for people that tried everything, and can't get it running, and are in desperation and lost.

General description first: The SONY XZ2 Compact is a phone with 2 slots. These phones don't have a recovery partition, so you cannot meaningfully boot into a recovery partition like on old phones. It now has a boot partition (2 of them - slot A and slot B), and you can boot an operating system from these slots. These slots are completely separate, you can boot an operating system in slot A and another separate one in slot B. These slots (from a user perspective) are separate, and there is very little interchange between them (or more or less none).

Prerequisits: TWRP, I used the Version from MartinX 2020-06-14_21-07-37_twrp_apollo.tar.gz , link is here: https://androidfilehost.com/?w=files&flid=306949
Use a STOCK TWRP
Extract the .img files with 7-zip (7-zip.org), until you have the .img file separate.

Newflasher:

[TOOL] Newflasher (xperia command line flasher)

Disclaimer: newflasher tool was made for testing and educational purposes, ME is not responsible for what you do on/with your device using newflasher, you must agree that you using newflasher on your own risk, I am not responsible if you brick...

forum.xda-developers.com

I used v42, probably newer versions work, too, try not to use an older version

Booting into fastboot: hold Volume-UP and then plugging a USB cable to the computer. The blue light should be lit, if fastboot is active, screen stays blank.

Booting into flash mode: hold Volume-DOWN and then plugging a USB cable to the computer. The green light should be lit, if flash mode is active, screen stays blank.

Now let's get to the process of flashing LOS:

Step 1 - Flash an original working SONY image into Slot A:
Boot into fastboot mode, so the blue light is on.
Type:
fastboot reboot bootloader
(Sometimes the computer doesn't recognise the phone after this command, then just unplug the USB, wait until the phone is off, and try again beginning Step 1. It can fail a couple of times, but it will also work in between).

fastboot --set-active=a
fastboot reboot bootloader

You can check that Slot A is active by typing the command
fastboot getvar all
in the output check the line current slot active: a

Run Newflasher (how to use Newflasher is beyond the scope of this post, google it) to flash an original stock SONY image. You need to be in flash mode for Newflasher with the green light lit.

Answer the first question what to do when done with Newflasher with 'p'=Power Off, and all others with 'n'=No.

When Newflasher completes, check the last few lines output, it should say setting slot A active and OKAY. That confirms that you flashed the original SONY image in Slot A.

You now have a fully working operating system in Slot A. However there is a bug in Newflasher and that bug destroys the boot process in Slot B, which means you'll be only able to boot Slot A, booting Slot B will fail.

Should you decide to boot the operating system (you don't have to), make sure you don't set up authentication (pin code, fingerprint), skip setting that up, so your data partition doesn't get encrypted.

Step 2 - Flash an original working SONY image into Slot B:
Boot into fastboot mode, so the blue light is on.
Type (similar to Step 1):
fastboot reboot bootloader
fastboot --set-active=b
fastboot reboot bootloader

You can check that Slot B is active by typing the command
fastboot getvar all
in the output check the line current slot active: b

WARNING: DO NOT BOOT Slot B, as it will fail 2-3 times (you'll notice the phone vibrating upon crash and reboot), because the phone will then put you back on Slot A, and you'll flash Slot A again. Make sure YOU DON'T BOOT the operating system in Slot B, or you'll end up in Slot A again.

Run Newflasher (how to use Newflasher is beyond the scope of this post, google it) to flash an original stock SONY image. You need to be in flash mode for Newflasher with the green light lit.

Answer the first question what to do when done with Newflasher with 'p'=Power Off, and all others with 'n'=No.

When Newflasher completes, check the last few lines output, it should say setting slot B active and OKAY. That confirms that you flashed the original SONY image in Slot B.

You now have a fully working operating system in Slot B. However there is a bug in Newflasher and that bug destroys the boot process in Slot A, which means you'll be only able to boot Slot B.

At this point in time, if you would try to boot into Slot A, it will boot up to the SONY logo, and then crash, and reboot up to the SONY logo, and then crash. Should you get stuck in that loop, insert a USB cable and hold Volume-UP, it'll catch the crashing loop, and you'll end up in fastboot.

Step 3 - Boot the original SONY image up to the home screen where the apps show:

Actually you should be in Slot B already, but if you are not:
Boot into fastboot mode, so the blue light is on.
Type (similar to Step 2):
fastboot reboot bootloader
fastboot --set-active=b
fastboot reboot bootloader

You can check that Slot B is active by typing the command
fastboot getvar all
in the output check the line current slot active: b

Boot the phone's operating original stock image in Slot B, until you are at the home screen with the apps. This sets up all the defaults for your phone, and updates any ROM images in the chips (like modem etc.).

Make sure you don't set up authentication (pin code, fingerprint), skip setting that up, so your data partition doesn't get encrypted.

Power off your phone.

Step 4 - Flash twrp into Slot B

Type (similar to Step 2):
fastboot reboot bootloader
fastboot --set-active=b
fastboot reboot bootloader

fastboot flash boot twrp.img

This will flash TWRP as boot in Slot B. Make sure in the screen output it was flashed in boot_b.

Should you make an error here, start with Step 1. The reason here is, we want LOS in Slot A, and not TWRP.

Boot your TWRP in Slot B.

WARNING: DO NOT flash VBMETA, it'll break the boot process, and you can start from Step 1.


Step 5 - Flash LOS into Slot A

Once TWRP is running, go to Wipe.

WARNING: DO NOT perform factory reset.

Go to Advanced Wipe, and ONLY WIPE 'Data' and 'Dalvic Cache'

WARNING: DO NOT WIPE System or Internal Storage. You'll loose mount points under Linux, and the LOS image flash will fail.

Go back to TWRP home screen.

From there go to Advanced and from there to ADB Sideload.

From the computer start installing your LOS image (sideload).

On the computer type:

adb sideload <Your LOS image>.zip.

ATTENTION: During flashing, the phone will show, which slot it flashes. It should flash and show: "flashing inactive Slot A". If you accidentally flash Slot B, start from the beginning Step 1.

Best results I had with the image from the LOS homepage https://download.lineageos.org/xz2c

Download the zip file, don't unpack it, use adb sideload to upload the zip file.

Forget about the Recovery image on the LOS homepage. You don't need it.

When flashing completes, you can wipe Delvic Cache.

WARNING: DO NOT WIPE 'cache', since a 2 slot phone doesn't have a cache partition, and it will fail to wipe it.

Do NOT install the TWRP app, skip this step.

Reboot

Step 6 - Boot LOS

LOS is in Slot A, TWRP is in Slot B.

You can alternate between the slots from fastboot.

fastboot reboot bootloader
fastboot --set-active=a
fastboot reboot bootloader

A reboot should boot LOS.

ATTENTION: When the LOS image has finished booting and you get to the date/time screen, the LOS will hang a while (30s). Just let it do it's job, I think (not sure), it's creating the data in the user partition. After 30s or so use the back key, and try setting the time again. This only happens on the very first boot.

Let me know as feedback, if I can clarify better or if this description is ok.

 

[WasserDragoon]

Hello,

if there is anything I can help with getting official support for LineageOS 18.1 pls let me know.

 

[landsome]

After a LOT of trial and error I am making a description, how to get a running LOS on your SONY XZ2 Compact Single SIM (and probably Dual SIM). This is not a description for people, who got it running the easy way. It's for people that tried everything, and can't get it running, and are in desperation and lost.

General description first: The SONY XZ2 Compact is a phone with 2 slots. These phones don't have a recovery partition, so you cannot meaningfully boot into a recovery partition like on old phones. It now has a boot partition (2 of them - slot A and slot B), and you can boot an operating system from these slots. These slots are completely separate, you can boot an operating system in slot A and another separate one in slot B. These slots (from a user perspective) are separate, and there is very little interchange between them (or more or less none).

Prerequisits: TWRP, I used the Version from MartinX 2020-06-14_21-07-37_twrp_apollo.tar.gz , link is here: https://androidfilehost.com/?w=files&flid=306949
Use a STOCK TWRP
Extract the .img files with 7-zip (7-zip.org), until you have the .img file separate.

Newflasher:

[TOOL] Newflasher (xperia command line flasher)

Disclaimer: newflasher tool was made for testing and educational purposes, ME is not responsible for what you do on/with your device using newflasher, you must agree that you using newflasher on your own risk, I am not responsible if you brick...

forum.xda-developers.com

I used v42, probably newer versions work, too, try not to use an older version

Booting into fastboot: hold Volume-UP and then plugging a USB cable to the computer. The blue light should be lit, if fastboot is active, screen stays blank.

Booting into flash mode: hold Volume-DOWN and then plugging a USB cable to the computer. The green light should be lit, if flash mode is active, screen stays blank.

Now let's get to the process of flashing LOS:

Step 1 - Flash an original working SONY image into Slot A:
Boot into fastboot mode, so the blue light is on.
Type:
fastboot reboot bootloader
(Sometimes the computer doesn't recognise the phone after this command, then just unplug the USB, wait until the phone is off, and try again beginning Step 1. It can fail a couple of times, but it will also work in between).

fastboot --set-active=a
fastboot reboot bootloader

You can check that Slot A is active by typing the command
fastboot getvar all
in the output check the line current slot active: a

Run Newflasher (how to use Newflasher is beyond the scope of this post, google it) to flash an original stock SONY image. You need to be in flash mode for Newflasher with the green light lit.

Answer the first question what to do when done with Newflasher with 'p'=Power Off, and all others with 'n'=No.

When Newflasher completes, check the last few lines output, it should say setting slot A active and OKAY. That confirms that you flashed the original SONY image in Slot A.

You now have a fully working operating system in Slot A. However there is a bug in Newflasher and that bug destroys the boot process in Slot B, which means you'll be only able to boot Slot A, booting Slot B will fail.

Should you decide to boot the operating system (you don't have to), make sure you don't set up authentication (pin code, fingerprint), skip setting that up, so your data partition doesn't get encrypted.

Step 2 - Flash an original working SONY image into Slot B:
Boot into fastboot mode, so the blue light is on.
Type (similar to Step 1):
fastboot reboot bootloader
fastboot --set-active=b
fastboot reboot bootloader

You can check that Slot B is active by typing the command
fastboot getvar all
in the output check the line current slot active: b

WARNING: DO NOT BOOT Slot B, as it will fail 2-3 times (you'll notice the phone vibrating upon crash and reboot), because the phone will then put you back on Slot A, and you'll flash Slot A again. Make sure YOU DON'T BOOT the operating system in Slot B, or you'll end up in Slot A again.

Run Newflasher (how to use Newflasher is beyond the scope of this post, google it) to flash an original stock SONY image. You need to be in flash mode for Newflasher with the green light lit.

Answer the first question what to do when done with Newflasher with 'p'=Power Off, and all others with 'n'=No.

When Newflasher completes, check the last few lines output, it should say setting slot B active and OKAY. That confirms that you flashed the original SONY image in Slot B.

You now have a fully working operating system in Slot B. However there is a bug in Newflasher and that bug destroys the boot process in Slot A, which means you'll be only able to boot Slot B.

At this point in time, if you would try to boot into Slot A, it will boot up to the SONY logo, and then crash, and reboot up to the SONY logo, and then crash. Should you get stuck in that loop, insert a USB cable and hold Volume-UP, it'll catch the crashing loop, and you'll end up in fastboot.

Step 3 - Boot the original SONY image up to the home screen where the apps show:

Actually you should be in Slot B already, but if you are not:
Boot into fastboot mode, so the blue light is on.
Type (similar to Step 2):
fastboot reboot bootloader
fastboot --set-active=b
fastboot reboot bootloader

You can check that Slot B is active by typing the command
fastboot getvar all
in the output check the line current slot active: b

Boot the phone's operating original stock image in Slot B, until you are at the home screen with the apps. This sets up all the defaults for your phone, and updates any ROM images in the chips (like modem etc.).

Make sure you don't set up authentication (pin code, fingerprint), skip setting that up, so your data partition doesn't get encrypted.

Power off your phone.

Step 4 - Flash twrp into Slot B

Type (similar to Step 2):
fastboot reboot bootloader
fastboot --set-active=b
fastboot reboot bootloader

fastboot flash boot twrp.img

This will flash TWRP as boot in Slot B. Make sure in the screen output it was flashed in boot_b.

Should you make an error here, start with Step 1. The reason here is, we want LOS in Slot A, and not TWRP.

Boot your TWRP in Slot B.

WARNING: DO NOT flash VBMETA, it'll break the boot process, and you can start from Step 1.


Step 5 - Flash LOS into Slot A

Once TWRP is running, go to Wipe.

WARNING: DO NOT perform factory reset.

Go to Advanced Wipe, and ONLY WIPE 'Data' and 'Dalvic Cache'

WARNING: DO NOT WIPE System or Internal Storage. You'll loose mount points under Linux, and the LOS image flash will fail.

Go back to TWRP home screen.

From there go to Advanced and from there to ADB Sideload.

From the computer start installing your LOS image (sideload).

On the computer type:

adb sideload <Your LOS image>.zip.

ATTENTION: During flashing, the phone will show, which slot it flashes. It should flash and show: "flashing inactive Slot A". If you accidentally flash Slot B, start from the beginning Step 1.

Best results I had with the image from the LOS homepage https://download.lineageos.org/xz2c

Download the zip file, don't unpack it, use adb sideload to upload the zip file.

Forget about the Recovery image on the LOS homepage. You don't need it.

When flashing completes, you can wipe Delvic Cache.

WARNING: DO NOT WIPE 'cache', since a 2 slot phone doesn't have a cache partition, and it will fail to wipe it.

Do NOT install the TWRP app, skip this step.

Reboot

Step 6 - Boot LOS

LOS is in Slot A, TWRP is in Slot B.

You can alternate between the slots from fastboot.

fastboot reboot bootloader
fastboot --set-active=a
fastboot reboot bootloader

A reboot should boot LOS.

ATTENTION: When the LOS image has finished booting and you get to the date/time screen, the LOS will hang a while (30s). Just let it do it's job, I think (not sure), it's creating the data in the user partition. After 30s or so use the back key, and try setting the time again. This only happens on the very first boot.

Let me know as feedback, if I can clarify better or if this description is ok.

So this works for 17.1 - but have you tried it on 18.1?

Asking because 17.1 works well for me following the official install method (via stock LOS recovery), whereas 18.1 fails.

 

[Garfield24]

So this works for 17.1 - but have you tried it on 18.1?

Asking because 17.1 works well for me following the official install method (via stock LOS recovery), whereas 18.1 fails.

It works on my phone, however:

I only have a 18.0 image from Olivier. Link is here: https://androidfilehost.com/?w=files&flid=320371

Use the 700MB image, the 200MB image (dated 20201206) probably won't work, the file size is too small. Not sure what the 200MB image is for. At the time of this post the image that worked was dated 20201205.

Anybody working on a 18.1 image, please post it here? I don't have the expertise to help with 18.1 image.

Directly flashing 18.0 image by Olivier crashed my phone, I am not sure why. There is no real reason I know of, but it did.

I first flashed official LOS 17.1 image from LOS homepage using the method above, and it worked. Boot the image to the home screen to intialise everything on LOS. Should it fail, you have a corrupt LOS image. I only had nightly builds available at the time of this post. Maybe that changes soon...

I then went back to slot B and booted TWRP again. I then sideloaded the LOS 18.0 .zip image from Olivier with adb sideload <imagefile.zip> without wiping anything. Don't wipe any partitions, just flash the 18.0 LOS image over the existing installation in Slot A.

When booting the LOS 18.0 image, it says data corrupt (I don't know why), and it boots into the LOS recovery and asks for a factory reset. Do a factory reset, you'll loose all data on the phone, so backup what needs to be backed up first. You probably need to install the apps again as well.

After the factory reset, the phone boots LOS 18.0 just fine.

I noticed there is no email client in the LOS 18.0 image from Olivier. Should you need it, the following tip:

IMPORTANT: When in TWRP (before you flash LOS 18.0), MOUNT System and Data in the mount menu.

You can then find the apk for the LOS email client in the LOS 17.1 image:

/system/system/product/app/Email/Email.apk
/system/system/product/app/Exchange2/Exchange.apk

Copy these apk in the TWRP file manager to /data/media/downloads

Boot LOS 17.1 and backup these apk files to your PC to install on LOS 18.0. The apk files are in your phone's download directory after the copy operation in TWRP.

The Exchange.apk is an extension package to the Email.apk to add Exchange client functionality.

IMPORTANT: After installing the apk on LOS 18.0, and even before you start them for the first time, go to Settings, and give "Email" and "Exchange" all permissions on your phone. Just allow everything. If you don't do that, the applications will crash upon start.

Hope that helps. Any questions, please ask.