Dan Stowell posted an article about how to package SC for debian/ubuntu, which seems to be the most sane way to build SC if you're using one of these distros.
To make things simpler (and avoid breaking your OS), I've created Docker recipes to create a clean Debian and Ubuntu building environments with the necessary dependencies to properly build deb packages.
In order to build the Docker image, enter to your prefered distro and:
$ docker build -t scdeb .
To run it after:
$ docker run --rm -it scdeb
Once you have a clean Debian installation working, just follow his advice.
The only thing that changes are:
gbp import-orig --pristine-tar --sign-tags ${path-to-fetched-tarball}
He describes ../tarballs as the directory where the repacked tar is placed, in my case this directory was simply .. (the directory above).
gbp buildpackage -S --git-export-dir=../buildarea
Same thing here: He describes ../buildarea as the directory where the repacked tar is placed, in my case this directory was simply .. (the directory above).
Also, since I'm not Felipe Sateler nor Dan Stowell, I wasn't able to sign the .changes or the source, so I used the flags -uc -us which doesn't sign the .changes / source respectively.
ie: gbp buildpackage -S -uc -us --git-export-dir=../
If everything went well, you'll see a bunch of .deb files placed in the directory above of the cloned repository.