I am trying to compile a executable for 32 bit in Backtrack 5R3 x64.

I do:
gcc -m file.c

In file included from /usr/include/features.h:378,
from /usr/include/string.h:26,
from bof.c:1:
/usr/include/gnu/stubs.h:7:27: error: gnu/stubs-32.h: No such file or directory

From Ubuntu 12.04 x64... I originally had the same error... So I did the following, and it works fine now.
#apt-get install libc6-dev-i386
#gcc -m32 file.c

However when I attempt to install libc6-dev-i386 for Backtrack 5R3, I get the following:
root@bt:~# sudo apt-get install libc6-dev-i386
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
libc6-dev-i386: Depends: libc6-i386 (= 2.11.1-0ubuntu7.8) but 2.11.1-0ubuntu7.10 is to be installed
Depends: libc6-dev (= 2.11.1-0ubuntu7.8) but 2.11.1-0ubuntu7.10 is to be installed
Recommends: gcc-multilib but it is not going to be installed
E: Broken packages