Merging leaves repo in "still merging" state

After executing a merge as suggested in the docs, a git status suggests that "you are still merging".

Bash:

git init mergable
cd mergable
echo a > a
git add .
git commit -m "initial"
git switch -c mergy
echo b > b
git add b
git commit -m "additional"
git switch master
cd ..
git clone mergable mergable-clone

Python:

import pygit2
r = pygit2.Repository("mergable-clone")
mergy = r.references["refs/remotes/origin/mergy"]
parents = [r.head.target, mergy.target]
r.merge(mergy.target)

r.create_commit(
    "HEAD",
    pygit2.Signature("aaa", "mergy@merge.ch"),
    pygit2.Signature("aaa", "mergy@merge.ch"),
    "merge",
    r.index.write_tree(),
    parents
)

Bash:

cd mergable-clone
git status

Returns:

On branch master
Your branch is ahead of 'origin/master' by 2 commits.
  (use "git push" to publish your local commits)

All conflicts fixed but you are still merging.
  (use "git commit" to conclude merge)

Another git commit silences the message.

Reproduce el problema usando los fragmentos de Bash y Python, luego inspecciona los puntos de entrada r.merge y r.create_commit y cómo actualizan el estado del merge. Confirma el comportamiento con git status; se considera terminado cuando el mismo flujo de commit ya no indique que el repositorio sigue en proceso de merge.