Worktree problem setting up for 15/stable

Since 15.1 is approaching I now wish to add a 15/stable work tree to my 
locally checked out base repo.

I currently have this, having pruned back the revisions I no longer use:

/usr/git/src          60bac4d6438b [main]
/usr/src.14-STABLE    d1160074500d [stable/14]
/usr/src.14.1-RELEASE 0892dff10444 [releng/14.1]

Thus I should be able to do, from the base (usr/git/src):

git worktree add --checkout /usr/src.15-STABLE stable/15

and establish that.

But when I do it it APPEARS to work:

[root@NewFS /usr/git/src]# git worktree add --checkout 
/usr/src.15-STABLE stable
/15
Preparing worktree (checking out 'stable/15')
Updating files: 100% (101670/101670), done.
HEAD is now at 4b6de64b99b9 ipfw_nptv6: fix handling the ifaddr removal 
event

However, when I go there and look....

[root@NewFS /usr/src.15-STABLE]# git branch
   list
+ main
+ releng/14.1
   stable/12
   stable/13
+ stable/14
* stable/15

Ok, except when I look in sys/conf/newvers.sh I find...

....

#       -v      Print TYPE REVISION BRANCH RELEASE VERSION RELDATE variables
#               like the -V command
#

TYPE="FreeBSD"
REVISION="14.4"
BRANCH="STABLE"
if [ -n "${BRANCH_OVERRIDE}" ]; then
         BRANCH=${BRANCH_OVERRIDE}
fi
unset RELEASE
unset VERSION

Which is not what I checked out and it appears there is no tracking 
information set either:

[root@NewFS /usr/src.15-STABLE]# git pull --ff-only
There is no tracking information for the current branch.
Please specify which branch you want to merge with.
See git-pull(1) for details.

     git pull <remote> <branch>

If you wish to set tracking information for this branch you can do so with:

     git branch --set-upstream-to=freebsd/<branch> stable/15

Its been a while since I set up the others, and they *are* working (a 
"git pull --ff-only" works as expected to update them) so I'm not sure 
what I'm missing here.... an attempt to pull from what should be the 
correct place results in a huge number of conflicts and a refusal to 
complete.

I assume my worktree command is wrong since I rather-obviously didn't 
get stable/15 in there but rather 14.4-STABLE (stable/14)

-- 
Karl Denninger
karl@denninger.net
/The Market Ticker/
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