Did something with format-patch or send-email break?

[Ian Eure <ian@retrospec.tv>]

I’m not sure of the precise mechanism employed, but I believe that 
that in the past, if I ran `git format-patch' and `git 
send-email', it would send an email to the right place.  This is 
implied by the manual, which doesn’t mention a patch submission 
email address, except for an issue number address when sending a 
patch series.

This doesn’t seem to work anymore; the output of `git 
format-patch' has no To: header populated, so `git send-email' 
asks me where:

    meson!ieure:~/Projects/guix/staging$ guix describe
    Generation 13	Jun 08 2024 17:39:39	(current)
      atomized 6bb138d
        repository URL: 
        https://codeberg.org/ieure/atomized-guix.git
        branch: main
        commit: 6bb138db5b7f56f399c9cb2e0b45fecaa8cd0182
      guix bc8a41f
        repository URL: https://git.savannah.gnu.org/git/guix.git
        branch: master
        commit: bc8a41f4a8d9f1f0525d7bc97c67ed3c8aea3111
    meson!ieure:~/Projects/guix/staging$ git log --oneline 
    HEAD^..HEAD
    bc8a41f4a8 (HEAD -> master, upstream/master) gnu: mes: Update 
    to 0.26.1.
    meson!ieure:~/Projects/guix/staging$ echo "changes" >> 
    gnu/packages/python-xyz.scm && git ci -am "changes"
    [master 88e3f97240] changes
     1 file changed, 2 insertions(+)
    meson!ieure:~/Projects/guix/staging$ git format-patch -1
    0001-changes.patch
    meson!ieure:~/Projects/guix/staging$ git send-email 
    0001-changes.patch
    0001-changes.patch
    To whom should the emails be sent (if anyone)?   C-c C-c

    meson!ieure:~/Projects/guix/staging$

Reproduced on Guix System, Guix on Debian (which the above output 
is from), and someone in #guix also reproduced it.

Is it broken?  Am I missing one of the numerous intricate fiddly 
bits of setup to make email patch flow work?  The manual’s "The 
Perfect Setup" section only mentions Geiser and yasnippet setup, 
which isn’t relevant to this.

Thanks,

  — Ian