magic file / invalid type 20 in mconvert()?

[Karen Pease]

I have absolutely no clue what this means.  Doing a local "make i386" while 
attempting to solve a problem that used to just manifest on the plague 
servers:

Executing(%doc): /bin/sh -e /var/tmp/rpm-tmp.77844
+ umask 022
+ cd /home/meme/code/fedora/nethack-vultures/FC-3
+ cd vultures-1.11.2
+ 
DOCDIR=/var/tmp/nethack-vultures-1.11.2-3-root-meme/usr/share/doc/nethack-vultures-1.11.2
+ export DOCDIR
+ rm -rf 
/var/tmp/nethack-vultures-1.11.2-3-root-meme/usr/share/doc/nethack-vultures-1.11.2
+ /bin/mkdir -p 
/var/tmp/nethack-vultures-1.11.2-3-root-meme/usr/share/doc/nethack-vultures-1.11.2
+ cp -pr nethack/README nethack/dat/license nethack/dat/history 
nethack/dat/cmdhelp nethack/dat/help nethack/dat/opthelp nethack/dat/wizhelp 
/var/tmp/nethack-vultures-1.11.2-3-root-meme/usr/share/doc/nethack-vultures-1.11.2
+ cp -pr slashem/readme.txt slashem/history.txt slashem/slamfaq.txt 
vultures/gamedata/manual/ 
/var/tmp/nethack-vultures-1.11.2-3-root-meme/usr/share/doc/nethack-vultures-1.11.2
+ exit 0
error: magic_file(ms, 
"/var/tmp/nethack-vultures-1.11.2-3-root-meme/usr/games/vulturesclaw/Guidebook.txt") 
failed: invalid type 20 in mconvert()
rpmbuild: rpmfc.c:1229: rpmfcClassify: Assertion `ftype != ((void *)0)' 
failed.
make: *** [i386] Aborted

I'm fairly new to the process of building RPMs for Fedora Extras.  What does 
this even mean?

	- Karen