From Linux Man Pages
git-fmt-merge-msg - Produce a merge commit message
git-fmt-merge-msg <$GIT_DIR/FETCH_HEAD
DESCRIPTION
Takes the list of merged objects on stdin and produces a suitable commit message to be used for the merge commit,
usually to be passed as the <merge-message> argument of git-merge.
This script is intended mostly for internal use by scripts automatically invoking git-merge.
RELATED
git-merge(1)
DOCUMENTATION
Documentation by Petr Baudis, Junio C Hamano and the git-list <git@vger.kernel.org>.
GIT
Part of the git(7) suite
CATEGORY