How to fix "/var/lib/pacman/db.lock" error on Arch Linux

I was trying to install firefox today on my Arch Linux machine, and I couldn't do it because of the error " Failed to init transaction (unable to lock database)" . This error happened right after I ran the command sudo pacman -S firefox .

[owlhowto@archlinux ~]$ sudo pacman -S firefox
[sudo] password for owlhowto: 
error: failed to init transaction (unable to lock database)
error: could not lock database: File exists
  if you're sure a package manager is not already
  running, you can remove /var/lib/pacman/db.lck
[owlhowto@archlinux ~]$ 

So then I thought maybe this is happening only when trying to download a package, so I tried to remove a package, and I got again the same errors.

[owlhowto@archlinux ~]$ sudo pacman -R screenshot
error: failed to init transaction (unable to lock database)
error: could not lock database: File exists
  if you're sure a package manager is not already
  running, you can remove /var/lib/pacman/db.lck
[owlhowto@archlinux ~]$ 

In this tutorial, you will learn how to fix "/var/lib/pacman/db.lock" error on Arch Linux.

Why does this error happen?

This error happens because the package database is being used by another app. And you won't be able to update, install or remove packages on your system. However, fixing this issue is easy, and it can be done via two ways.

1) By Updating your package database

2) By deleting the /var/lib/pacman/db.lock

Solution #1: Update Package Database

To update package database on Arch Linux, you can use pacman. Launch terminal and run the following command

sudo pacman -Syu

Solution #2: Delete db.lock File

You can use the rm command to delete the db.lock file which is located on pacman directory /var/lib/pacman/. Now to delete this file, run the command below

sudo rm /var/lib/pacman/db.lock

After deleting it, you can verify that db.lock got deleted successfully. To do this, you can try to view the content of this file by using the cat command.

cat /var/lib/pacman/db.lock

When deleted, the command above should return "cat: /var/lib/pacman/db.lock: No such file or directory" on your terminal. This means the db.lock file was successfully deleted and you should be able to manage packages on Arch Linux.

Conclusion

In this tutorial, you learned how to fix the error "/var/lib/pacman/db.lock" when using pacman package manager on Arch linux to manage packages. I hope our tutorial helped you to fix this error.