gem5 v26.0 staging branch created!

[BobbyRBruce]

The release-staging-v26-0 branch is available for testing as we prepare the gem5 v26.0 release.

The RELEASE-NOTES.md on the staging branch outlines the release contents, including major features, compatibility changes, and migration guidance. Please review it and flag any errors or omissions.

PR #3559 will merge the staging branch into stable for the v26.0.0.0 release. You can follow that PR for progress toward the release.

A reminder of the release process

The gem5 release process provides a two-week staging period for testing and addressing release-critical issues. We run the full gem5 test suite against the staging branch, and release readiness depends on the test results and resolution of any blocking problems.

Two weeks is typically sufficient to address the concerns raised. Assuming no unresolved issues require more time, we expect to release on Monday, October 19, 2026.

Once the branch is ready, we complete the release procedures, merge staging into stable, and tag the release on stable as v26.0.0.0. A separate announcement will confirm when the official release is available.

How can I get and test v26.0 staging?

To obtain a fresh checkout:

git clone --branch release-staging-v26-0 \
    https://github.com/gem5/gem5.git gem5-v26.0-staging
cd gem5-v26.0-staging

Please build this branch and test it with your usual configurations and workloads.

What should I do if I find a bug or have a fix?

If you find a bug on the staging branch and can fix it, please submit a patch! Contributions from anyone testing the staging branch are very welcome. Ideally, submit your fix as a pull request to develop first. Once it is reviewed and merged, I will cherry-pick the relevant commits into release-staging-v26-0.

Please notify me (@BobbyRBruce) if your PR needs to be included in staging. Tag me on the PR, explain why the fix is needed for v26.0, and describe how to reproduce the bug and how you checked the fix. You are also welcome to link the PR in this discussion.

If you cannot fix the bug, please still open a ticket in the gem5 GitHub issue tracker. You do not need a solution to report a problem. Clearly identify that you tested v26.0 staging and include the commit tested, build and run commands, configuration, host environment, relevant logs, and expected versus observed behavior. For regressions, include a known working version if possible.

Staging is reserved for changes that cannot wait until the next release, such as critical bug fixes. All changes undergo the usual review process, and maintainers decide which are appropriate for inclusion. Continue submitting normal development work to develop; new features and changes that can wait will be considered for a subsequent release.

Thank you to everyone contributing code, reviews, testing, and bug reports to gem5 v26.0!

Bobby