Hi. While we are deciding whether to make this arch=all or not, can we please add the Multi-Arch:same tag? This would enable co-installation, letting cross-builds work as they should. Since the contents of libeigen2-dev are identical on every arch, this one-line change to debian/control should be sufficient. If it's helpful, I can prepare the new package, but I cannot upload it as I am not a DD. dima