GPG error during apt-get upgrade

["Todd A. Jacobs" <nospam@codegnome.org>]

I'm getting the following error when running "apt-get upgrade":

    Reading package lists... Done
    W: GPG error: http://security.debian.org stable/updates Release:
    Unknown error executing gpgv
    W: GPG error: http://security.debian.org testing/updates Release:
    Unknown error executing gpgv
    W: You may want to run apt-get update to correct these problems

Obviously, GPG is having some sort of problem with the signatures from
the security source, but I'm not sure how to track it down. Anyone have
any advice about what to do next?

-- 
Unabashedly littering the information superhighway with detritus like
this for over 15 years now.