arch linux/vifm: updated

wiki/linux/package_manager.md

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+# Package Managers
+
+Package managers are important programs to get software onto your system.
+
+## Arch Linux: Pacman and Yay
+
+In [Arch Linux](/wiki/linux/arch-linux/arch-linux.md) there are 2 main types of
+package managers.
+The first is pacman, the default package manager.
+
+For the second type there are many different managers to chose from.
+Those managers are handling for the Arch User Repositories (AUR).
+In this article yay is used as the go to AUR manager.
+yay is also a wrapper for pacman so yay can be used instead of pacman to
+install and update both AUR and main repository programs.
+It features the same syntax.
+
+### Bugfixes
+
+The following section describes problems that can arise when using pacman or
+yay.
+
+#### Update Mirrorlist
+
+After a while not updating the system it is possible for the mirrorlist to be
+outdated.
+This can be fixed by updating it with the following command:
+
+```sh
+curl -o /etc/pacman.d/mirrorlist https://archlinux.org/mirrorlist/all/
+```
+
+#### Error while importing keys
+
+Both `yay` and `pacman` use gpg keys to confirm the package manager gets the
+right package.
+It is possible that it runs into errors when importing new keys.
+If this happens you should try to restart your gpg key server with
+`gpgconf --kill all`.
+
+#### Unknown public key
+
+If the error `ERROR: One or more PGP signatures could not be verified!`, you
+have to manually receive the key and trust it.
+This is done by running the following lines:
+
+```sh
+gpg --recv-key <KEYID>
+gpg --lsign <KEYID>
+```
+
+Where <KEYID> is the placeholder of the identification string of the key.
+It usually gets gets printed in the line above the error looking like
+`FAILED (unknown public key <KEYID>)`.
+
+#### Error while updating `is marginal trust`
+
+Both `yay` and `pacman` use gpg keys to confirm the package manager gets the
+right package.
+It is possible that it runs into errors when importing new keys.
+If the error `[...] Key [...] is marginal trust` occurs while updating the
+system, it can be fixed by running the following commands and then restarting
+the update process of the package manager.
+
+```sh
+pacman -Sy archlinux-keyring
+pacman-key --populate archlinux
+pacman-key --refresh-keys
+```