This is my bundle of setup scripts to make using pbuilder on Ubuntu a sane and comprehensible experience for modifying and patching your own system.
The goal here is that everything stays semi-associated to your home directory. A non-goal at the moment is removing the sudo root dependency, since that's hard.
A very specific goal is to support incremental builds - i.e. when you upgrade a package with library dependencies, each build can depend on the next while being installed on your system.
This approach is definitely not intended for hermetic or reproducible builds - the goal here is to hack packages on your system in a way which leaves you the ability to rollback by installing older versions.
I have found this system works well for me.
Run ./setup-pbuilder-repo in the root of the repository.
This will do a few things: generate a new GPG key as your trusted pbuilder key,
and setup the basic repository structure in your $HOME/.cache and $HOME/pbuilder
folders.
It will then also ask for sudo permissions and create /etc/apt/sources.list.d/pbuilder.list
to make your built packages visible to both pbuilder and your system.