Version number suggests Ubuntu changes

Today, I was updating an Ubuntu package whose maintainer in Debian has a @canonical.com address.

When I was building the source package, I kept getting an error:

Version number suggests Ubuntu changes, but Maintainer: does not have Ubuntu address

This error crashed dpkg-source and prevented me from building the source package.

Upon looking into the code (/usr/share/perl5/Dpkg/Vendor/Ubuntu.pm), I found that this errors only when DEBEMAIL is defined in the environment with a @ubuntu.com address ; a warning is issued otherwise.

So if you ever have this problem, it's easily fixed by unsetting DEBEMAIL:

$ unset DEBEMAIL