# New experimental autopkgtest backend uses pconr for faster containment

> **Key takeaway:** A new experimental backend for autopkgtest, autopkgtest-virt-pconr, provides lightweight containment with an initsystem using the erofs format.

**Published:** 2026-10-14T00:00:00+00:00 
**Source:** Planet Debian (Developer Blogs) 
**Category:** distro-planet 
**Canonical URL:** https://fosswire.org/news/new-experimental-autopkgtest-backend-uses-pconr-for-faster-c.html 

## Summary
Freexian collaborators have introduced autopkgtest-virt-pconr, an experimental backend for the Debian testing framework. It occupies a middle ground between unshare-based testing and full containers like Incus or LXC. By utilizing the erofs base image format, it enables rapid booting and reverting during automated tests.

## Technical details of autopkgtest-virt-pconr
- Provides a containment layer that runs an **initsystem** without requiring heavy infrastructure like **Incus** or **LXC**.
- Uses **erofs** as the base image format to ensure fast boot and revert cycles.
- Built upon the **pconr** module, which serves as a foundation for **unschroot** and enhanced **mmdebstrap** security.
- Development of this backend led to fixes for concurrency issues in **asyncvarlink** and a bug fix in **systemd** upstream.

## Why it matters
This provides Debian developers with a more efficient way to run automated package tests with higher fidelity than unshare, but with less overhead than full virtualization.