【Git】error: unknown option `initial-branch=main'

gitでエラーが出た；

% git init --initial-branch=main
error: unknown option `initial-branch=main'
usage: git init [-q | --quiet] [--bare] [--template=<template-directory>] [--shared[=<permissions>]] [<directory>]

    --template <template-directory>
                          directory from which templates will be used
    --bare                create a bare repository
    --shared[=<permissions>]
                          specify that the git repository is to be shared amongst several users
    -q, --quiet           be quiet
    --separate-git-dir <gitdir>
                          separate git dir from working tree

--initial-branchオプションをご存知でない！？

gitのバージョンが古いだけでした。

gitをアプデしましょう。

以上。

蛇足

エラー吐いたときのGitのバージョン；

% git --version
git version 2.24.1

Gitは、どうやら、Homebrewでインスコしてた模様；

% where git
/usr/local/bin/git  <- Homebrew
/usr/bin/git        <- macOSランタイム？

% ls -go /usr/local/bin/git
lrwxr-xr-x  1   28 12 20  2019 /usr/local/bin/git@ -> ../Cellar/git/2.24.1/bin/git

% ls -l /usr/bin/git
-rwxr-xr-x  76 root  wheel  167120  5 10 06:30 /usr/bin/git*

最新のバージョンを確認します。

まずはbrew updateでHomebrew（自身）を最新版にアプデします；

% brew update
...

% brew -v
Homebrew 3.5.4
Homebrew/homebrew-core (git revision 1abcad8993b; last commit 2022-07-09)
Homebrew/homebrew-cask (git revision 0ec7c70cf3; last commit 2022-07-09)

Gitの最新安定版は2.37.0のようです；

% brew outdated git
git (2.24.1) < 2.37.0

% brew info git
git: stable 2.37.0 (bottled), HEAD
Distributed revision control system
https://git-scm.com
/usr/local/Cellar/git/2.24.1 (1,554 files, 45.5MB) *
  Poured from bottle on 2019-12-20 at 23:31:19
From: https://github.com/Homebrew/homebrew-core/blob/HEAD/Formula/git.rb
License: GPL-2.0-only
==> Dependencies
Required: gettext ✔, pcre2 ✘
==> Options
--HEAD
    Install HEAD version
==> Caveats
The Tcl/Tk GUIs (e.g. gitk, git-gui) are now in the `git-gui` formula.
Subversion interoperability (git-svn) is now in the `git-svn` formula.

zsh completions and functions have been installed to:
  /usr/local/share/zsh/site-functions

Emacs Lisp files have been installed to:
  /usr/local/share/emacs/site-lisp/git
==> Analytics
install: 267,859 (30 days), 859,304 (90 days), 3,005,421 (365 days)
install-on-request: 262,165 (30 days), 840,650 (90 days), 2,942,147 (365 days)
build-error: 36 (30 days)

というわけで、Gitをアプデします；

% brew upgrade git

以上で、Gitをアプデできました；

% git --version
git version 2.37.0

--initial-branchオプションもちゃんと使えるようになっていました；

% git init --initial-branch=main
Initialized empty Git repository in /Users/hoge/Desktop/test/.git/

めでたしめでたし

参考

qiita.com