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· 3 min read
Jaime Rodríguez-Guerra
Jannis Leidel

With this 23.10.0 release we are changing the default solver of conda to conda-libmamba-solver! 🥳 🚀

libmamba builds on libsolv, a much faster solver from openSUSE. The previous "classic" solver is based on pycosat/Picosat and will remain part of conda for the foreseeable future. A fallback is possible and available.

· 6 min read
Ken Odegard

The September 2023 releases included updates to five conda community projects: conda, conda-build, conda-libmamba-solver, conda-index, and pycosat! 🎉 Each of these have been released to both main and conda-forge.

Changes in Conda 23.9.0

To update conda, run:

conda install -n base conda=23.9.0

📢 Special Announcement 📢


Conda's default solver will change to conda-libmamba-solver in a special 23.10.0 release in the near future!

You can already benefit from conda-libmamba-solver today by configuring your conda installation to use it (e.g. by running conda config --set solver libmamba).

The current "classic" solver is based on pycosat/Picosat and will remain part of conda for the foreseeable future. A fallback is possible and available.

Additional details on this change as well as the full announcement can be found in the conda 23.9.0 changelog.

· 7 min read
Pinak Datta

Welcome to the second issue of the conda Community Newsletter! We're excited to bring you the latest updates and insights, packed with valuable information and exciting developments.

In this issue, we've got a diverse range of topics to cover, including Upcoming Events, new tools like conda-store, thought-provoking discussions on conda's free nature, plugin hooks, and intriguing projects like Pandata. Plus, we'll delve into recent releases that promise to enhance your conda experience.

But that's not all! We'll also highlight one job opportunity and share news about recent talks from Travis Hathaway and Bianca Henderson, now available for public consumption.

· One min read
Dave Clements

Image credit: Is conda free?

Hi All,

A new blog post, titled "Is conda Free?", answers your questions about:

  1. what is free to use in the conda ecosystem (most everything),
  2. what parts of that ecosystem may not be free, and
  3. under what clearly defined circumstances those maybe-not-free parts can still be free after all.

There has been confusion around this since Anaconda introduced its Terms of Service in 2020. I hope the post banishes that confusion (forevermore!). The post is framed as a discussion, introducing why there might be confusion about this topic, and then diving into the details.

Happy reading, and using the conda ecosystem too!
Dave C

PS: If reading the discussion doesn't grab you then go straight the summary and just pretend you read the whole thing.

PPS: Spoiler alert! ... Yes.

· 4 min read
Travis Hathaway

With the latest conda release (23.7.2 at the time this post was written), the ability to define two new plugin hooks was introduced: "pre command" and "post command". These two new plugin hooks give plugin authors the ability to execute code before and after conda commands are run. In this blog post, we provide more details on how and why you may use these to extend the default behavior of conda.

· 5 min read
Bianca Henderson

The July 2023 releases are here! 🎊 Conda 23.7.0, 23.7.1, 23.7.2, and conda-build 3.26.0 are now available on both main and conda-forge channels.

Changes in Conda 23.7.0/23.7.1/23.7.2

To update conda, run:

conda install -n base conda=23.7.2

✨ What's New? ✨

In the latest release of conda, new pre- and post-command plugin hooks that allow you to run your code before or after a conda subcommand are now available, along with a much improved subcommand plugin hook and plugin infrastructure. There is also a new health check for conda doctor that detects altered packages in an environment by comparing expected and computed sha256 checksums, as well as a much-expanded API and command docs (conda env!).

· 2 min read
Dave Clements

Image credit: EUREF Campus Berlin

PackagingCon 2023

  • 26-28th October
  • Berlin and online
  • Submission deadline: 31st July
  • Early registration ends: 8th September

PackagingCon 2023 will bring together different software packaging ecosystems to share best practices and discuss common challenges in software packaging. From Python’s pip to Rust’s cargo to Julia’s Pkg, from Debian apt over Nix, to Homebrew, conda and mamba, and from vcpkg to Spack. The 2021 conference drew 350+ participants and featured over 60 presentations.

· 4 min read
Jannis Leidel
Jaime Rodríguez-Guerra

Over a year ago, the conda team at Anaconda, together with conda developers at Quansight and QuantStack, announced the release of a new solver for conda based on the libraries that the mamba project had developed on top of the venerable libsolv project.


The default solver change for conda will be occurring in a special 23.10.0 release (not in 23.9.0). See the special announcement here.


  • From July 2023 on, conda-libmamba-solver will be part of the various installers. The default conda solver is still classic. Look out for the release of miniconda, Anaconda Distribution and miniforge soon.
  • From September 2023 on, the default conda solver will be libmamba. classic will be available via --solver=classic, if needed.
  • At some point in the future, we'll discuss whether the classic solver is kept around, maintained as a separate plugin, and/or deprecated for good. Feedback welcome!

· 7 min read
Dave Clements
Pinak Datta

Welcome to the first ever conda community newsletter! The newsletter will highlight recent and upcoming activity that is relevant to the conda community. This first issue highlights community gathering spaces, upcoming events, the new rattler library, channel updates from conda-forge and Bioconda, a summary or recent conda-related web content, and finally releases and announcements.

We are hoping these will become a semi-regular feature in the conda landscape going forward. If you have an item to include in a future newsletter, please let us know by posting it to the Conda Communications Matrix Channel or by creating an issue in the Conda Communications GitHub Repo.