Tag to be used with the 21.X branches of atlas/athena.
Updates in this tag:
  - Added FindHJets.cmake for finding the HJets generator;
  - Fixed the generation of .d files for Ninja, to make dictionary generation behave correctly with this build tool;
  - Added some extra find-modules to AtlasLCG;
  - Stopped setting up the Cairo and Pango packages when using graphviz.

Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.25:
  - Added FindHJets.cmake for finding the HJets generator;
  - Added prmon as a new external to AthenaExternals;
  - Fixed the generation of .d files for Ninja, to make dictionary generation behave correctly with this build tool;
  - Updated FindQt5.cmake to both fix a bug in it, and to make it create "simple" variables for the include directories and linked libraries to use.

Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.24:
  - Added Findcx_Oracle.cmake, Finddecorator.cmake and Findpyxml.cmake, as these LCG python packages are used without explicit declarations in some Athena packages.

Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.23:
  - Updated CheckerGccPlugins to ignore the usage of gSystem;
  - Fixed the setup of QT5_LIBRARY_DIRS in FindQt5.cmake;
  - Stopped setting up the Cairo and Pango packages when using graphviz.

Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.22:
  - Updated CheckerGccPlugins;
  - Update to CLHEP to CLHEP_2_4_0_1_atl02 to fix the bug reported in CLHEP-154;
  - Updated AtlasCMake/AtlasLCG to use C++17 by default, with all compilers;
  - Added nlohmann_parser as a new external;
  - Added VP1LightExternals, with some new external packages;
  - Updated AtlasLCG to provide find-modules for all the new python modules/externals introduced with LCG_95.

Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.21:
  - Various updates to CheckerGccPlugins;
  - Fixes to the standalone ROOT build;
  - Fixes to Reflex dictionary builds, including how Ninja builds are done;
  - Updates to the locations where some LCG externals are picked up from.

Tag to be used with the 21.X branches of atlas/athena.
Updates in this tag:
  - Updated the location from which some "older" LCG packages get picked up, so they would now be picked up from EOS.

Tag to be used with the 21.X branches of atlas/athena.
Updates in this tag:
  - Updated the Davix and ROOT build configurations to make ROOT find our version of Davix successfully once more;
  - Fixed an issue with the Reflex dictionary builds that made compilation impossible on macOS.

Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.20:
  - Introduced fixes for AnalysisBaseExternals on Ubuntu and macOS;
  - Added FindCURL.cmake to AtlasLCG to be able to use CURL from the LCG releases if necessary;
  - Updated the code handling Doxygen to work successfully with LCG_94;
  - Added a lot of CMake changes to make the code work smoothly with CMake >=3.13.

Tag to be used with the 21.X branches of atlas/athena.
Updates in this tag:
  - Introduced the LCG_IGNORED_SYSTEM_PATHS and LCG_SYSTEM_IGNORE_PATH variables for blacklisting selected directories when searching for externals;
  - Various fixes meant for macOS;
  - Fixed Davix-0.7.1's build in the absence of a python interpreter;
  - Added some fixes to how Doxygen is used by atlas_project(...).

Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.19:
  - Introduced LCG_IGNORED_SYSTEM_PATHS and LCG_SYSTEM_IGNORE_PATH for influencing globally what directories to ignore during the build and environment setup script generation.
  - Fixed the RPM dependency problem introduced when FindTBB.cmake started setting up TBB_VERSION using tbb/tbb_stddef.h.

Tag to be used with the 21.X branches of atlas/athena.
Updates in this tag:
  - Made AnalysisBaseExternals functional on the PPC64 platform.
  - Added some dictionary improvements for detecting upstream changes more reliably that should trigger a dictionary re-generation. Also made the dictionary generation more reliable on MacOS Mojave.
  - Updated AnalysisBaseExternals and AthAnalysisExternals to LCG_94a. This meant updating the version of ROOT and Davix built for AnalysisBaseExternals.

Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.18:
  - Updated Acts to allow forcing a clean re-build of the project whenever necessary.
  - Updated the Acts build to propagate additional build configuration settings to the external.

Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.17:
  - Updated AnalysisBaseExternals to build TBB, and make the standalone version of ROOT build against that version of TBB;
  - Made it possible to build AnalysisBaseExternals on PPC64 and in C++17 mode;
  - Updated Acts to version 0.7.3;
  - Updates to CheckerGccPlugins for GCC 9;
  - Updated all projects to use LCG_94a.

Tag to be used with the master branch of atlas/athena.
Update(s) since 2.0.15:
  - Made the (Reflex) dictionary generation code a bit smarter, to better detect "upstream header changes".

Tag to be used with the master branch of atlas/athena.
Updates since 2.0.15:
  - Updated the CLHEP and G4 builds to properly clean up when switching to a different version of CLHEP/G4. Allowing for CI friendly version updates of these two externals.
  - Updated the ROOT dictionary building CMake code to better detect when Reflex dictionaries need to be re-generated in an incremental build.

Tag to be used with the master branch of atlas/athena.
Updates since 2.0.15:
  - Added FindSuperchic.cmake and updated FindHerwig3.cmake to work with newer Herwig versions;
  - Updated to CLHEP 2.4.0.1;
  - Updated to Geant4 10.4.2.1;
  - Added GeoModel as an external to AthenaExternals and AthSimulationExternals;
  - Added a speedup to calling find_package(LCG ...) in user projects.

Tag to be used with the 21.X branches of atlas/athena.
Updates in this tag:
  - Added FindSuperchic.cmake for finding that new generator (not functional in this release yet);
  - Made FindHerwig3.cmake more robust, and functional with newer Herwig versions;
  - Backported some technical AtlasLCG updates from the master branch.

Tag to be used with the 21.X branches of atlas/athena.
Updates in this tag:
  - Updated the build of Davix to happen on any linux system that should be able to build it. (Changed from only building it on SLC6 and CC7.)
  - Updated the Geant4 version to 10.1.patch03.atlas07.
  - Updated the lwtnn version to 2.8.
  - Suppressed some warnings from new CMake versions.

Tag to be used ONLY WITH NIGHTLY BUILDS of the master branch of atlas/athena.
Updates since 2.0.14:
  - Update gcc checker plugins to avoid some false positives from the
    thread-safety checker and aldo to copy documentation here.
  - Fix ACTS version used in the build.
  - Update lwtnn to 2.8.
  - Minor cmake fixes