git-notes, how do they work?

[Ulrich Spoerlein <uspoerlein@gmail.com>]

Dear all,

I cannot figure out how notes are supposed to stay around and not be
GC'ed eventually, seeing as nothing references them, usually.

But let me start from the beginning, I'm using svn2git to convert a
large repository and I want it to store metadata in the notes, which it
does just fine. However, after a while of running (and I suspect garbage
collection is to blame) the older notes start to disappear and only HEAD
has a note attached to it. This means that the notes, as pushed to
github, are only partially complete.

IIUC refs/notes/commits points to the latest note, which points to HEAD.
However, there's no reference that points to the note pointing to
HEAD^1, so how will it not be garbage collected? How can it be pushed to
a remote repository?

I understand that notes cannot point to older notes, as that would make
removing/adding notes from/to older commits quite a hassle.

So, what am I doing wrong here? How can I avoid notes from disappearing
so that each and every one of it remains in the repo?

Cheers,
Uli