emacs 20.3-7: bad build
The version of emacs 20.3-7 on ftp.debian.org is seriously screwed up.
It gets various sorts of arithmetic errors, font-lock colors are
psychedelic, customization gives messages saying "you shouldn't be
seeing this", etc. I rebuilt the package from source on my system and
now it seems healthy.
I ran across a bad bug in bits/endian.h which might be affecting any
number of packages, possibly including emacs: it expects gcc to set
__BIG_ENDIAN or __LITTLE_ENDIAN for it (there's a comment about how
PowerPC can be either big- or little-endian). gcc doesn't do that, so
endianness remains indeterminate. This is guaranteed to break things.
I've submitted a bug report against libc6-dev 2.0.100-2.