Unclear updater error message every time MacVim starts

Steps to reproduce

1. Install MacVim via Macports:

sudo port install macvim

2. Start MacVim

Expected behaviour

No error dialog should be displayed or an explanation of the underlying problem and the steps to solve it should be given.

Version of MacVim

MacVim r183 (Vim (null))

MacVim installation method

MacPorts

Environment

Tahoe 26.5.1
Macbook Pro M3 Max
No terminal - opened via double click in e.g. a .txt file or directly on the application

Logs and stack traces

I could not find anything relating to MacVim in /var/log/* - what is this console log the error message refers to?

Vim and MacVim configuration where issue is reproducable

$ cat .vimrc 
set guifont=Hack:h14
set linespace=2

How was MacVim launched?

• by launching MacVim.app in macOS (by using the Dock, Spotlight, or the open command)
• by running mvim/gvim in the terminal

Issue has been tested with clean configuration

• by running mvim --clean (or gvim, supplied by MacVim distribution). You can also use the File → "New Clean Window" menu item within MacVim.
• by running vim --clean (in terminal, supplied by MacVim distribution)
• by running vim --clean (in terminal, other suppliers, e.g. /usr/bin/vim)

まず、issue に記載されているクリーンな設定を使って、MacPorts 経由でインストールした MacVim.app の起動時に updater ダイアログを再現します。ダイアログが参照しているコンソールログを確認し、起動時の updater の処理経路を追跡します。ダイアログが削除されるか、原因と解決策が明確に説明されれば完了です。