I upgraded my Debian testing install to sid today, and was met with this lovely error:

Removing xfonts-bolkhov-75dpi ...
usage error: unrecognized option
Usage: update-fonts-dir DIRECTORY ...
update-fonts-dir { -h | --help }
This program is a wrapper for mkfontdir(1x) that is primarily useful to Debian
package maintainer scripts. See update-fonts-dir(8) for more information.
Options:
-h, --help display this usage message and exit
dpkg: error processing xfonts-bolkhov-75dpi (--remove):
subprocess post-removal script returned error exit status 2

I cannot get this package to go away. Any help would be greatly appreciated.

Strange, xfonts-util provides update-font-dirs and is only present in unstable.

Look into /var/lib/dpkg/info/xfonts-bolkhov-75dpi.postrm, and try to see if there is a syntax error ( very unlikely, people have tested this)