As you have successfully installed AUR packages this is not an issue. However, if you care to benefit from a ‘teaching moment’ this is how you could check that the prerequisites are installed, and install them if needed:
1. Check that both base-devel and git are installed:
pacman -Qi base-devel git
2. Read the output.
3. If these are not installed, install them:
sudo pacman -Syu base-devel git
…and reboot
Notice here that base-devel was already installed and up to date.
Reinstalling was unnecessary.
Try again to update or build something using pamac.
If this still fails then you might have deeper issues specific to your system. I suggest ‘specific to your system’ because the commands complete without issue here;
If problems persist, please open a new support thread.
Thank you all so much for all your help!! Printer is installed! The yay solution from Nachlese worked. The printer driver now shows up as the recommended driver when adding a printer in settings.
The actual problem with pamac-cli that was initially preventing the AUR package build, however, isn’t confirmed to be fixed. I’d strongly suggest you open a new Support thread for that.
Although you have solved the issue and perhaps for followers of this thread I was having the same problems but followed the instructions here; Install Package From AUR on Arch or Manjaro - Linux Nightly and they worked like a dream first time.
That article contains incorrect instructions which will eventually result in problems with the Pamac databases:
Install Package From AUR With Pamac (command line)
With Pamac installed, you can access the AUR via command line in addition to GUI. The build option will retrieve the specified package from the AUR and then compile and install it. Let’s use Pamac to install QDirStat from the AUR:
$ sudo pamac build qdirstat
sudo should never be used with pamac. It changes the database file permissions, eventually resulting in this type of error message when users try to install or update apps via Pamac:
Failed to read AUR data from /var/tmp/pamac/dbs/sync/packages-meta-ext-v1.json.gz : Error opening file /var/tmp/pamac/dbs/sync/packages-meta-ext-v1.json.gz: No such file or directory
The following command is then required to fix it:
sudo rm -rf /var/tmp/pamac
Pamac will prompt the user for their password if and when required.
Edit: I just posted a comment to that page advising of the error