Linus Arver [off-list ref] writes:

quoted

 * An very old but still severe bug in tagged versions would want to
   be fixed ideally not on top of 'maint' but on top of the latest
   tagged version in the same maintenance track.  E.g. if the commit
   X introduced the bug, you may ask "git describe --contains X" the
   oldest version the commit appears in, say "v2.30.0-rc2-gXXXXXX".
   Then you would run "git checkout -b fix v2.30.9" to start the
   branch to fix it.

In this example, are we using v2.30.9 as a starting point, not v2.30.0
because v2.30.9 is the latest tagged version that is in 'maint'?

Answering my own question, I now see that there are branches named
`maint-2.30`, `maint-2.31`, etc. And `2.30.9` is the latest version in
the `maint-2.30` branch.