pbuilder

pbuilder is a tool used on Debian and derivatives to build Debian packages inside a clean, isolated chroot environment. It uses debootstrap to create a minimal base system for a chosen distribution and architecture, and then runs the standard Debian packaging build process inside the chroot. This separation from the host helps ensure that build dependencies come only from declared build-dependencies, supports reproducible builds, and reduces the risk of contamination from the building machine.

How it works: A chroot is prepared for a given distribution and architecture, and the package is built inside that environment using the usual tools such as dpkg-buildpackage or debuild, often with fakeroot to simulate root privileges. pbuilder can update the chroot, install build dependencies automatically, and collect build logs and resulting .deb files. To speed repeated builds, wrappers like cowbuilder provide a copy-on-write backend that reuses a base chroot across builds.

Configuration and usage: Global options are defined in a pbuilder configuration file, typically /etc/pbuilder/pbuilderrc, with per-project customization possible via a local pbuilderrc. The built chroots are stored in a cache, commonly under /var/cache/pbuilder, with separate bases for each distribution and architecture. The user supplies a source package (for example a .dsc file) or sources, and pbuilder performs the build within the prepared chroot. Commands commonly include pbuilder create to set up a chroot and pbuilder build to build a package.

See also: sbuild, cowbuilder, debootstrap.