I just played around upgrading a FreeBSD 14.3p6 VM to 15.0-RELEASE via FreeBSD-base.
I still have not figured out how to do that with the official repos, but after building packages locally i was able to upgrade the boot environment and reboot in a working #freebsd15 installation!
Has anyone got this working with the official base repo?
If anyone is interested, here are my notes about upgrading locally (Notes in picture alt for copy paste).

```
env ABI=FreeBSD:15:amd64 IGNORE_OSVERSION=yes pkg -c /mnt/upgrade/ install -r FreeBSD-base FreeBSD-pkg-bootstrap
```
Then upgrade the base packages
```
env ABI=FreeBSD:15:amd64 IGNORE_OSVERSION=yes pkg -c /mnt/upgrade/ upgrade -r FreeBSD-base
```
Check, if FreeBSD-set-base is installed:
```
env ABI=FreeBSD:15:amd64 IGNORE_OSVERSION=yes pkg -c /mnt/upgrade/ install -r FreeBSD-base FreeBSD-set-base
```
upgrade all other packages
```
env ABI=FreeBSD:15:amd64 IGNORE_OSVERSION=yes pkg -c /mnt/upgrade/ upgrade
```
Temporarily activate boot env and reboot
```
bectl activate -t 15.0
shutdown -r now
```](https://media.bsd.cafe/bsdmmedia01/media_attachments/files/115/674/160/876/526/884/original/ff7283dad4ab279f.png)