Many of the on-line instructions and tutorials are quite complicated. Why? It was easy for me:
sudo apt-get install sbuild
To build a virtual machine:
mk-sbuild --distro=ubuntu --arch=i386 precise
this will create a schroot in /var/lib/schroots/precise-i386. Note how it appends the architecture to the schroot name. Also note that the first time you run mk-sbuild, it’ll show you a configuration file and configure your environment. I didn’t change anything in the config file, I used it “as it was”. When it prompts you to log out, do it, otherwise things won’t work.
OK now you want to build a package using your chroot with sbuild:
sbuild -A -d precise package.dsc
This will build the package on precise for ALL available architectures. Note that -d is just “precise”; the -A flag will tell sbuild to build architecture: any packages for all available architectures (so if you have amd64 and i386 chroots, it’ll do the right thing and build two packages).
If you want to build arch-specific packages:
sbuild -d precise-i386 package.dsc
This will magically build for the given architecture (i386). Note that arch: any packages will also be built.
You can also specify the arch as a parameter (but then you have to leave it out of the -d name):
sbuild -d precise --arch=i386 package.dsc
This will not work:
sbuild -d precise-i386 --arch=i386 package.dsc