If you are downloading a new application or upgrading a system and you face the problem that indicates the GPG Signature is not valid, you should to this things:
if the problem with gpg is comming from archlinux packages, you need to reinstall this package to get latest keys.
sudo pacman -Sy
sudo pacman -S archlinux-keyring
If you're experiencing issues with GPG signatures in Parch Linux, follow these steps to temporarily disable signature verification, install the updated keyring, and then restore normal behavior.
Edit the /etc/pacman.conf file and locate the [ppr] and [pcp] sections. Change their SigLevel to Never:
[ppr]
SigLevel = Never
Include = /etc/pacman.d/parch-mirrors
[pcp]
SigLevel = Never
Include = /etc/pacman.d/parch-mirrors
Now, install the latest parchlinux-keyring package:
sudo pacman -Sy parchlinux-keyring
This will install the trusted GPG keys required to validate Parch Linux packages.
Once the keyring is installed, revert the SigLevel settings for [ppr] and [pcp] back to:
[ppr]
SigLevel = Optional TrustAll
Include = /etc/pacman.d/parch-mirrors
[pcp]
SigLevel = Optional TrustAll
Include = /etc/pacman.d/parch-mirrors
If you need to use Parch Linux live and you need more space for the live root, you need to run this command:
sudo mount -o remount,size=1G /run/archiso/cowspace
The command Above would increase the root file system to 1G , if you need more space change the 1G in command to something else for example: 4G