An IT person is not worth their salt, if they do not experiment with any equipment or device they lay their hands on. Here is my experience with the XOSP Nougat version for Sony Xperia ZR (dogo).
I enthusiastically installed XOSP on my Sony Xperia ZR using this ROM file XOSP-OFFICIAL-20170527-dogo.zip, downloaded from the https://xosp.org web page. Was great to see it rebooted and was working like a charm, till I discovered two problems with it.
1. I lost root completely.
2. It would not install open_gapps nor XOSPSettings app.
Any attempt to install SuperSU failed. It gave error, signature not verified. In most recoveries, you get option to ignore signature verification. But, in case of XOSP, this was not possible. Somehow, I tried to then reflash Resurrection Remix 5.8.3 over this version, and met with error that I cannot overwrite the latest XOSP ROM with an older release of XOSP or any other after market firmware. My struggle to get relief did not end.
I needed all above features irrespective of whatever happened. I patiently waited for the new release of XOSP and reinstalled it. Still no luck and I ended up with a handicapped Sony Xperia ZR on which I installed F-Droid, installed the Terminal Emulator from jackpal from the F-Droid Marketplace. To my consternation, there was no root on XOSP. Maybe the developers missed something. I also found K-9 Mail and Twidere on F-Droid. Installed them both, K-9 Mail worked very well, but Twidere, nope.
Now with patience running thin and a lot of angst of being “incapable” of downgrading, I spent the rest of the time, figuring how to get twrp back on the phone. I kept getting “Command failed” errors. Now, going back seemed a very remote possibility.
Then, I browsed my old data backups and found that I had once used clockworkmod of cyanogen, to back up my phone. And to my surprise, found a boot.img file within it. Some hope, but risky.
I went ahead and started the phone in bootloader mode.
On the Linux terminal, I typed:
sudo fastboot flash boot boot.img <enter>
To my surprise, it was successful.
Next I tried:
sudo fastboot flash recovery twrp.img <enter>
This gave the same “Command failed” error.
Anyway, I rebooted the phone and got into recovery mode. Guess what? I was greeted by the clockworkmod menu where I could now toggle the signature verification and do any damn thing I now wanted to do, and upon which I had wasted many days. Yippee….
After that, I copied Resurrection Remix ROM file to an SD Card, inserted that card into the Sony Xperia ZR and rebooted into recovery. Now I was able to flash from sdcard1 and installed Resurrection Remix onto the phone.
This done, I rebooted the phone and found, I was into Resurrection Remix 5.8.3, Nougat. Problem solved.