[arch-general] Complete mess after having attempted to install Nvidia drivers‏‏

[m a]

> Boot from the LiveCD and chroot to your system

I have already done that (having followed the relevant Archbang wiki)
but, once I attempt to install anything, I get this:
error: GPGME error: Bad file descriptor
error: xorg-server: missing required signature
error: failed to commit transaction (invalid or corrupted package (PGP
signature))
Errors occurred, no packages were upgraded.