To avoid any "failed to execute command" errors when no orphans are found, use the following command for .
However pacman does not offer the possibility to keep a number of past versions and is therefore more aggressive than paccache default options.
The pacman database distinguishes the installed packages in two groups according to the reason why they were installed: Package (6) Old Version New Version Net Change Download Size extra/libmariadbclient 10.1.9-4 10.1.10-1 0.03 Mi B 4.35 Mi B extra/libpng 1.6.19-1 1.6.20-1 0.00 Mi B 0.23 Mi B extra/mariadb 10.1.9-4 10.1.10-1 0.26 Mi B 13.80 Mi B defines a package repository to be used.
First find what package contains the missed library and then locate it in the pacman cache ( flag as you just unpacked system files and pacman does not know about it. Some issues have been reported regarding network problems that prevent pacman from updating/synchronizing repositories.Pacman will correctly replace our shared library file with one from package.   When installing Arch Linux natively, these issues have been resolved by replacing the default pacman file downloader with an alternative (see Improve pacman performance for more details).Instead of having to enter all the numbers except the ones you do not want, it is sometimes more convenient to select or exclude packages or ranges of packages with the following syntax: Pacman can update all packages on the system with just one command.This could take quite a while depending on how up-to-date the system is.The following command synchronizes the repository databases and updates the system's packages, excluding "local" packages that are not in the configured repositories: Tip: Add the above command to a pacman post-transaction hook to be notified if a transaction orphaned a package.
This can be useful for being notified when a package has been dropped from a repository, since any dropped package will also be orphaned on a local installation (unless it was explicitly installed).
In the case that pacman crashes with a "database write" error while removing packages, and reinstalling or upgrading packages fails thereafter, do the following: If installing Arch with an outdated ISO, you are likely prompted to import PGP keys. If you are unable to add the PGP key successfully, update the keyring or upgrade does not contain the key, until it is updated.
Pacman tries to bypass this by a lookup through a key-server, which might not be possible e.g.
To remove all the cached packages that are not currently installed, and the unused sync database, execute: Warning: One should avoid deleting from the cache all past versions of installed packages and all uninstalled packages unless one desperately needs to free some disk space.
This will prevent downgrading or reinstalling packages without downloading them again. Pacman always lists packages to be installed or removed and asks for permission before it takes action.
Note: Packages often have a series of optional dependencies which are packages that provide additional functionality to the application, albeit not strictly required for running it.