git repack -A -d doesn't remove objects found in alternates?

Hello,

I wonder if I do something wrong, or if I just don't understand something:

	ukl@dude04:~/work$ git version
	git version 2.30.2

	ukl@dude04:~/work$ git clone https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
	...
	ukl@dude04:~/work$ cd linux/
	ukl@dude04:~/work/linux$ du -sh .git/objects
	2.6G    .git/objects
	ukl@dude04:~/work/linux$ echo "/ptx/work/user/git/linux.git/objects" > .git/objects/info/alternates

	ukl@dude04:~/work/linux$ git repack -A -d
	...
	ukl@dude04:~/work/linux$ du -sh .git/objects/
	2.6G	.git/objects/

I would have expected a drastic size decrease from git repack after the alternate is added. Compare with:

	ukl@dude04:~/work$ time git clone --reference /ptx/work/user/git/linux.git https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux-with-reference
	Cloning into 'linux-with-reference'...
	Updating files: 100% (73605/73605), done.

	ukl@dude04:~/work$ du -sh linux-with-reference/.git/objects/
	4.0K	linux-with-reference/.git/objects/

Can you spot the bug (or the wrong expectation)?

Thanks Uwe