Retrieve missing GPG using makepkg

Original posted by @FadeMind on Manjaro forum

Issue

Some files are signed with developers GPG sign. Without validation of source tarbals, build package fails. For automatically downloading and adding new keys to LOCAL GPG database follow once this guide.

Install GnuPG

sudo pacman -S gnupg pinentry --needed --noconfirm

Enable following services sockets as normal user:

systemctl --user enable gpg-agent.socket
systemctl --user start gpg-agent.socket
systemctl --user enable dirmngr.socket
systemctl --user start dirmngr.socket

Files and content

$HOME/.gnupg/dirmngr.conf

keyserver hkps://pgp.mit.edu
keyserver hkps://hkps.pool.sks-keyservers.net
keyserver hkp://keyserver.ubuntu.com:80

$HOME/.gnupg/gpg.conf

keyserver hkps://pgp.mit.edu
keyserver hkps://hkps.pool.sks-keyservers.net
keyserver hkp://keyserver.ubuntu.com:80
keyserver-options auto-key-retrieve
require-cross-certification
keyring /etc/pacman.d/gnupg/pubring.gpg
use-agent

$HOME/.gnupg/gpg-agent.conf

NOTICE: If You are in NON-KDE use pinentry-qt or pinentry-gtk-2 .

default-cache-ttl 300
max-cache-ttl 999999
pinentry-program /usr/bin/pinentry-qt

### uncomment GTK2 or kwallet variant instead of QT if you needed.
# pinentry-program /usr/bin/pinentry-gtk-2
# pinentry-program /usr/bin/pinentry-kwallet

pinentry-kwallet is part of kwalletcli from AUR You need build and install (via yay/pacaur tool) if you want store passwords in kwallet.

Reload GPG Agent

gpg-connect-agent reloadagent /bye