Comment 8 for bug 1512992

Problem still present in 16.04 LTS
LOG:
(Reading database ... 216786 files and directories currently installed.)
Preparing to unpack .../zlib1g-dev_1%3a1.2.8.dfsg-2ubuntu4_i386.deb ...
Unpacking zlib1g-dev:i386 (1:1.2.8.dfsg-2ubuntu4) ...
dpkg: error processing archive /var/cache/apt/archives/zlib1g-dev_1%3a1.2.8.dfsg-2ubuntu4_i386.deb (--unpack):
 trying to overwrite '/usr/include/i386-linux-gnu/zconf.h', which is also in package lib32z1-dev 1:1.2.8.dfsg-2ubuntu4
Processing triggers for man-db (2.7.5-1) ...
Errors were encountered while processing:
 /var/cache/apt/archives/zlib1g-dev_1%3a1.2.8.dfsg-2ubuntu4_i386.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)

I encountered this while trying to setup an Android build environment/kernel building environment.

Forcing as mentioned above works.