Can't run "dpkg --add-architecture i386" on 12.04 64-bit to run eclipse ADT

make sure the only file present in /etc/dpkg/dpkg.cfg.d/ is "multiarch"

ls /etc/dpkg/dpkg.cfg.d/

if output is

multiarch

execute the following commands as it is else replace "multiarch" with the name of file present in that directory.

sudo sh -c "echo 'foreign-architecture i386' > /etc/dpkg/dpkg.cfg.d/multiarch"

The above command will add i386 architecture.

12.04 is not fully Multiarch.

To get android dev environment up and running:

 sudo apt-get install ia32-libs openjdk-6-jdk:i386