0. Conclusion about pacman-key & GPG using proxy

0-1. Manually add option

--keyserver-options http-proxy=http://ID:PASS@PROXY_IP:port

sudo gpg --keyserver-options http-proxy=http://ID:PASS@PROXY_IP:port --keyserver hkp://keyserver.ubuntu.com --recv-keys 29C71CE612B57264

0-2. Add `http-proxy http://ID:PASS@proxy_IP:PORT` to belows.

/etc/gnupg/dirmngr.conf
/etc/pacman.d/gnupg/dirmngr.conf

sudo vi /etc/gnupg/dirmngr.conf

http-proxy http://ID:PASS@proxy_IP:PORT

sudo vi /etc/pacman.d/gnupg/dirmngr.conf

http-proxy http://ID:PASS@proxy_IP:PORT

And run follows or restart PC.

systemctl --user daemon-reload
systemctl --user restart dirmngr.service

Following is the process for fixing the keyring error at that time.

1. keyring error, during upgrade system

sudo pacam -Syyuu
....

### https://zenn.dev/miwarin/articles/e0ca2e9d78a1614fe296
## エラー: ruby-rexml: "Ike Devolder <ike.devolder@archlinux.org>" の署名は信頼されていません
:: ファイル /var/cache/pacman/pkg/ruby-rexml-3.2.6-1-any.pkg.tar.zst は破損しています (無効または破損し たパッケージ (PGP 鍵))。
ファイルを削除しますか? [Y/n]

2. confirm key

pacman-key --list-sigs | fgrep "Daniel M. Capella"

fgrep: warning: fgrep is obsolescent; using grep -F
gpg: 注意: 信用データベースが、書き込み不能です
uid           [期限切れ] Daniel M. Capella <polyzen@archlinux.org>
sig      N   29C71CE612B57264 2024-02-02  Daniel M. Capella <polyzen@archlinux.org>
uid           [  充分  ] Daniel M. Capella <polyzen@archlinux.org>
sig      N   EA4F7B321A906AD9 2024-02-09  Daniel M. Capella <polyzen@archlinux.org>

3. sign key

sudo pacman-key --lsign-key EA4F7B321A906AD9

  -> Locally signed 1 key.
==> 信頼データベースを更新...
gpg: 次回の信用データベース検査は、2024-11-18です

4. sign another key of same person

same person's another key but no user ID ...?
Something is wrong?

sudo pacman-key --lsign-key 29C71CE612B57264

  -> Locally signed 1 key.
==> 信頼データベースを更新...
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: key 786C63F330D7CB92: no user ID for key signature packet of class 10
gpg: 公開鍵DB323392796CA067は、署名よりも3037日、新しいものです
gpg: key 1EB2638FF56C0C53: no user ID for key signature packet of class 10
gpg: key 1EB2638FF56C0C53: no user ID for key signature packet of class 10
gpg: marginals needed: 3  completes needed: 1  trust model: pgp
gpg: 深さ: 0  有効性:   1  署名:  25  信用: 0-, 0q, 0n, 0m, 0f, 1u
gpg: 深さ: 1  有効性:  25  署名: 103  信用: 1-, 0q, 0n, 24m, 0f, 0u
gpg: 深さ: 2  有効性:  75  署名:  30  信用: 75-, 0q, 0n, 0m, 0f, 0u
gpg: 次回の信用データベース検査は、2024-11-18です

Same kind of error occurs during upgarde

sudo pacman -Syyuu

## エラー: ruby-rexml: "Ike Devolder <ike.devolder@archlinux.org>" の署名は信頼されていません
:: ファイル /var/cache/pacman/pkg/ruby-rexml-3.2.6-1-any.pkg.tar.zst は破損しています (無効または破損し たパッケージ (PGP 鍵))。
ファイルを削除しますか? [Y/n]

5. refresh key

gpg or pacman-key should use proxy.
so add --keyserver-options manually
use Ubuntu key-server, because default server now work at that time.

sudo gpg --keyserver-options http-proxy=http://ID:PASS@PROXY_IP:port --keyserver hkp://keyserver.ubuntu.com --recv-keys 29C71CE612B57264

gpg: *警告*: homedir '/home/hoge/.gnupg'の安全でない所有
gpg: 鍵29C71CE612B57264: 公開鍵"Daniel M. Capella <polyzen@archlinux.org>"をインポートしました
gpg:           処理数の合計: 1
gpg:             インポート: 1

all key becomes [full] and it seems to be fine !

LANG=C sudo pacman-key --list-sigs | grep -i capella
uid           [  full  ] Daniel M. Capella <polyzen@archlinux.org>
sig      N   29C71CE612B57264 2024-02-02  Daniel M. Capella <polyzen@archlinux.org>
uid           [  full  ] Daniel M. Capella <polyzen@archlinux.org>
sig      N   EA4F7B321A906AD9 2024-02-09  Daniel M. Capella <polyzen@archlinux.org>

6. just in case, update keyring...

sudo pacman -S archlinux-keyring manjaro-keyring

警告: archlinux-keyring-20241015-1 は最新です -- 再インストール
警告: manjaro-keyring-20230719-3 は最新です -- 再インストール

パッケージ (2) archlinux-keyring-20241015-1  manjaro-keyring-20230719-3

合計インストール容量:        1.76 MiB
最終的なアップグレード容量:  0.00 MiB

==> manjaro.gpg からキーを追加...
==> キーリングの信頼されたキーに署名...
  -> Locally signed 1 key.
==> 所有者信頼値をインポート...
==> 信頼データベースを更新...

gpg: 次回の信用データベース検査は、2024-11-18です

7. upgrade system without error

sudo pacman -Syyuu

reference