6.32.14

Patch release of the 6.32 cycle. The following items were addressed:

• #18301 - Performance issue seen by CMS for ROOT's use of tbb::task_arena
• #18556 - Class methods not available to python in cases of transient data members of private nested class type
• #18236 - Missing lock deep inside TClassEdit::GetNormalizedName
• #18519 - Concurrency issue with TClassEdit::ResolveTypedef and TClass::GetListOfMethods
• #18520 - Missing lock deep inside TClassEdit::ResolveTypedef
• #18792 - Thread problem in TEnum::GetEnum
• #18863 - ThreadSanitizer reports data race between TTree::Branch and TCling::Evaluate
• #18312 - Problem with cmake 4.0.0
• #17566 - Issue with prebuilt binaries for MacOS 15.x

v6.36.00

First release of the v6.36 series.
🗒️ Release notes
💾 Install instructions

The new ROOT comes with many great features that have the potential of making you even more productive 🏆 - see release notes and highlights below! The effort made by the contributors, experiments and core developers is testified by the 202 items in the ROOT trackers that have been addressed for this release.

As previously announced, the 6.36 cycle supersedes the STS 6.34 one, which will be stopped in June.

Highlights

🐍 Python Interface

• Unified Histogram Interface (UHI): ROOT histograms now implement UHI ,enhancing interoperability with external python libraries for plotting and enabling pythonic indexing and slicing for histogram manipulation - see the doc here!
• The interoperability of ROOT and NumPy arrays was enhanced in many areas.

💾 RNTuple

• The RNTuple core API moved from experimental to production, out of the Experimental namespace, and the RNTuple libraries are now always built with ROOT (i.e., no need to explicitly enable the root7 build option anymore). User code using the production API will now benefit from ROOT's regular API stability.
• Production classes include the RNTupleReader and RNTupleWriter, and associated classes. Some advanced classes, such as the RNTupleParallelWriter, will be moved to production in a later release.

📚 Documentation

• A veritable Tutorials Renovation Campaign took place: it is now more intuitive to navigate through the individual parts of the ROOT tutorials, our collection of code examples. Some tutorials were added to showcase the new features, some were modernized to modern C++ standards and some were moved to the legacy folder.

📈 RDataFrame

• Local and distributed APIs are now made uniform, and the distributed RDataFrame module is out of the Experimental namespace 🥳
  RNTuple processing has been improved with automatic conversion of collection types to the ergonomic ROOT::RVec, and you can now save the modified RNTuple with Snapshot
• Many improvements to the well-known RDataFrame functionalities were added, including parsing of CSV files, Display, Report, AsNumpy, reading pandas dataframes and numpy arrays.

📊 RooFit

• Creating HistFactory models from many histograms is up to an order of magnitude faster. In an ATLAS example, the workspace creation time went from 15 minutes to 1:30 minutes!
• Automatic differentiation, powered by Clad, is transparently available to users, providing improved numerical stability as well as much more runtime performance.

🧑‍💻 C++ Interpreter

• Existing code can now be interpreted and just-in-time compiled according to the C++23 standard for the platforms that support it.

6.36.00-rc1

First release candidate of the 6.36.00 release
🗒️ Release notes
💾 Install instructions

This is the ROOT release targeting 2026 LHC data taking. It comes with many new features (see the preliminary release notes) as well as improved stability: more than 180 items in the ROOT trackers have been addressed for this release.

Please note that 6.36 will be supersede the 6.34 release. Patch releases of 6.34 will be provided until June 30th 2025.

Cheers,
Danilo for the ROOT Project

6.34.08

This release includes minor bug fixes as well as the changes necessary to build and run on macOS Sequoia 15.4 and XCode 16.3.

6.32.12

This release includes minor bug fixes as well as the changes necessary to build and run on macOS Sequoia 15.4 and XCode 16.3.

The following items were addressed:

• [#17992] - Spurrious auto parsing when looking up a TClass
• [#17978] - root build fails in clad when using more than one job
• [#17753] - Race condition in TClass::fStreamerImpl value for emulated classes.

6.34.06

Patch release of v6.34 series.

🗒️ Release notes
💾 Install instructions

This branch includes minor bugfixes and changes in the code to adapt it to the evolving ROOT's testing infrastructure. Notable examples are the reduced dependency on the webserver of ROOT's tests or changes required by ATLAS FastFrames framework. JSRoot has been updated to version 7.8.2.

The following items were addressed:

• #10096 - heap-use-after-free in ~TTreeReader
• #17456 - Test failures when compiling ROOT with gcc 15
• #17753 - Race condition in TClass::fStreamerImpl value for emulated classes.
• #17992 - Spurrious auto parsing when looking up a TClass

6.34.04

Patch release of v6.34 series.

🗒️ Release notes
💾 Install instructions

This release includes a few minor fixes in RDataFrame, as well as a mechanism was added to specify binding options when opening sockets with TSocketServer.
Moreover, the items listed below were addressed:

• [ROOT-7372] - Accessing complex map branches crashes in PyROOT
• [ROOT-10482] - pullHist and residHist biased
• [#12841] - [ntuple] prefer IO constructor in RField::GenerateValue()
• [#14007] - Cannot create a RNtuple into a TDirectory
• [#15473] - Segmentation fault when building with the mold linker
• [#16189] - TFile::k630forwardCompatibility does not apply to new files correctly
• [#16560] - Issue using TColor and saving canvas to ROOT format
• [#17291] - [RF] Parameter ordering bug in RooFormulaArgStreamer
• [#17305] - The ONNX.Tile5D test in tmva/sofie/test/TestCustomModelsFromONNX.cxx writes array elements beyond the last element in the array
• [#17321] - [RF] Unused Class rule
• [#17442] - [Python] Regression in std::bytes support with cppyy inside ROOT
• [#17444] - ROOT doesn't compile with gcc-15
• [#17472] - RooEllipse not drawn in notebooks with %jsroot on

6.32.10

Patch release of v6.32 series.

🗒️ Release notes
💾 Install instructions

In this release, minor fixes for RDataFrame were integrated, and a mechanism was added to specify binding options when opening sockets with TSocketServer. In addition, these items were addressed:

• #17444 - ROOT doesn’t compile with gcc-15
• #16189 - TFile::k630forwardCompatibility does not apply to new files correctly

6.34.02

Patch release of v6.34 series.

🗒️ Release notes
💾 Install instructions

This release includes a few minor fixes in RDataFrame and RooFit, besides the item below. Moreover, built-in Davix was patched to build with GCC14 while waiting for the new Davix release.

Items addressed in this release:

• [#17190] - Compiler error (GCC 14.2.0 on Linux)
• [#17222] - Regression in Python ownership for histograms within subdirectories with ROOT 6.34.00
• [#17223] - TFileMerger leaves files open resulting in corrupt metadata

v6.34.00

Six months after the 6.32 release, 6.34 is now available. The new ROOT comes with many new features (see the release notes) as well as improved stability: more than 200 items in the ROOT trackers have been addressed for this release.

Some highlights:

• RNTuple: the first version of the RNTuple on-disk binary format was finalized. Future versions of ROOT will be able to read back RNTuple data written as of this release. Check out this talk at the CHEP 2024 conference and this blogpost to learn more about RNTuple, the new HEP data storage software technology!
• Python interface: more stability and functionality, also thanks to the latest Cling C++ interpreter version, powered by LLVM 18.
• Machine learning training directly from ROOT datasets much larger than the memory of the machine is now possible. Read the data with RDataFrame, apply transformations if needed and then feed your favourite ML tool. For a full description, see the presentation at CHEP 2024
• RDataFrame: scaling on many cores was improved, memory usage significantly reduced. Moreover, the interface for distributed execution has been expanded for a more rewarding user experience.
• RooFit: the power of automatic differentiation can be now transparently used thanks to CLAD - see this talk at the ICHEP 2024 conference.
• Graphics: Javascript interactive visualisation is now the default for notebooks, moreover the web graphics functionality has been further expanded.
• Build infrastructure: not a functionality per se, but a boost in stability. This release was integrated and tested on more than ten Linux flavours (on x86, ARM and NVidia GPUs), four types of Windows configurations as well as four macOS versions (yes, the Apple Beta was there too!)

Please note that 6.34 is a short term support release. As such, it is not meant to be used for data taking. It will be superseded by the 6.36 release, which is foreseen in May 2025. Patch releases of 6.34 will be provided until June 30th 2025.