Unikraft releases v0.19.1 (Pan)

This release contains fixes and improvements to Unikraft.

We are proud to announce the latest release of Unikraft, v0.19.1. This release contains fixes that improve the stability and application support of Unikraft. For a full breakdown, please check out the changelog.

Changes in `0.19.1`#

lib/vfscore: Harmonize handling of paths in *at syscalls (#1647) by @andreittr
lib/posix-process: Fix clone() return value on thread create (#1649) by @michpappas
lib/uksched: Rework waitqueues to use thread data (#1651) by @andreittr
lib/ukbitops: Rework bit find ops for consistency (#1652) by @andreittr
lib/ukboot: Skip graceful shutdown on last child release (#1653) by @michpappas
lib/ukrandom: Fix undefined behavior (#1655) by @michpappas
lib/posix-process: Fix stack corruption in signal delivery (#1657) by @michpappas
lib/vfscore: Fix uninitialized mutex in dentry (#1675) by @andreittr

⚠️ Compatibility notice:

In libukbitops:

uk_ffs() / uk_ffsl() have been updated to return values consistent with libc's ffs() / ffsl() and __builtin_ffs() / __builtin_ffsl().
Previous exact behavior of uk_ffs() / uk_ffsl() is now provided by uk_lssb() / uk_lssbl().
uk_fls() / uk_flsl() are replaced by uk_mssb() / uk_mssbl().

Catalog Updates#

Both the catalog and catalog-core repositories have received updates, primarily from the Community and Development Lab event, from Google Summer of Code applicants and from Unikraft Summer Workshop. Types of updates are:

Adding a new application to the catalog.
Updating the application version in the catalog.
Updating the naming schema.
Updating the unikernel runtime used.
Updating the configuration or documentation to have the application working with recent versions of Unikraft.

Community Activities#

Unikraft Summer Workshop 2025#

Unikraft Summer Workshop 2025 (USW'25) is a free and virtual workshop held by members of the Unikraft community. It focuses on cloud-native applications and on the unikernel technology that powers efficient and high performance cloud deployments.

USW'25 took place for the weeks, between June 23 and July 12, 2025. It ended with a contributor hackathon on Saturday, July 12, 2025, 9am-5pm CEST.

22 participants from all over the world took part in the event. In the end, they worked on 5 projects that resulted in contributions to Unikraft community repositories:

Java on Unikraft
Click on Unikraft
WARM on Unikraft
Update Node Version in Applications
Update Python Version in Applications
FreeBSD Libc in Unikraft

All participants received a diploma and premium access to Unikraft Cloud.

Congratulations to everyone and keep contributing 🤝

GSoC'25 Projects#

Unikraft is part of Google Summer of Code 🤩 5 projects are currently under way in the Unikraft community:

Project: Expanding the Unikraft Software Support Ecosystem
Project: Fine-Tuning Unikraft's Performance
Project: Update Newlib and Pthread-embedded Libraries
Project: Testing Framework for Unikraft Builds
Project: Updating Unikraft Application Libraries