includes MRs: https://gitlab.cern.ch/atlas/athena/-/merge_requests/41738 Try to fix HepMC3 nightlies warning related to MCTester https://gitlab.cern.ch/atlas/athena/-/merge_requests/41753 Make some python codes HepMC3 compatible (small MR) https://gitlab.cern.ch/atlas/athena/-/merge_requests/41754 Further updates of McEventCollection codes https://gitlab.cern.ch/atlas/athena/-/merge_requests/41811 Try to fix nightly cmake https://gitlab.cern.ch/atlas/athena/-/merge_requests/41832 use PathResolver to find G4particle_whitelist.txt, add missing dependency in... https://gitlab.cern.ch/atlas/athena/-/merge_requests/41836 Manual sweep of 41708 to master https://gitlab.cern.ch/atlas/athena/-/merge_requests/41900 Added complete Pythia_8 ART tests https://gitlab.cern.ch/atlas/athena/-/merge_requests/42046 GeneratorObjectsTPCnv: Fix fourvector initialization for hepmc3 case https://gitlab.cern.ch/atlas/athena/-/merge_requests/42080 added yoda to root converter for Pythia ART tests https://gitlab.cern.ch/atlas/athena/-/merge_requests/42136 Removal of useless comments in Generators https://gitlab.cern.ch/atlas/athena/-/merge_requests/42141 Fix GenEventCnv_p1 for HepMC3 (one line) https://gitlab.cern.ch/atlas/athena/-/merge_requests/42147 Modified ART tests for Pythia8 https://gitlab.cern.ch/atlas/athena/-/merge_requests/42150 Deal with weights for HepMC3 https://gitlab.cern.ch/atlas/athena/-/merge_requests/42157 update TauFilter to include changes from rel. 21.6, fix the loop over vertices https://gitlab.cern.ch/atlas/athena/-/merge_requests/42199 Modified ART test for Pythia8 https://gitlab.cern.ch/atlas/athena/-/merge_requests/42245 corrected minor issues for test 02 https://gitlab.cern.ch/atlas/athena/-/merge_requests/42269 Fixes of Tau Filter https://gitlab.cern.ch/atlas/athena/-/merge_requests/42281 added PowhegControl ART tests https://gitlab.cern.ch/atlas/athena/-/merge_requests/42359 Various optimizations to the Pythia8B package https://gitlab.cern.ch/atlas/athena/-/merge_requests/42377 added dcube tests for PowhegControl ART tests and fixed some typo https://gitlab.cern.ch/atlas/athena/-/merge_requests/42398 Remove printout of PACKAGE_VERSION https://gitlab.cern.ch/atlas/athena/-/merge_requests/42444 corrected dcubename typo for Powheg ART test https://gitlab.cern.ch/atlas/athena/-/merge_requests/42470 sync MCTC and save flag for PU content with 21.2/21.6 https://gitlab.cern.ch/atlas/athena/-/merge_requests/42479 Correct typo for ART tests https://gitlab.cern.ch/atlas/athena/-/merge_requests/42595 Remove PACKAGE_VERSION printouts https://gitlab.cern.ch/atlas/athena/-/merge_requests/42611 Sherpa_i: Let CMake define OpenLoops path https://gitlab.cern.ch/atlas/athena/-/merge_requests/42694 Remove linking to SGTests https://gitlab.cern.ch/atlas/athena/-/merge_requests/42707 add harmonised TauFilter, include most recent PowhegControl updates, update to.. https://gitlab.cern.ch/atlas/athena/-/merge_requests/42723 Use IClassIDSvc header from GaudiKernel https://gitlab.cern.ch/atlas/athena/-/merge_requests/42781 Externals Update, master branch (2021.04.21.) https://gitlab.cern.ch/atlas/athena/-/merge_requests/42839 remove duplicated lines from PowhegControl registry. Add missing common fragment for Herwig7 https://gitlab.cern.ch/atlas/athena/-/merge_requests/42846 GeneratorFilters: Fix clang warning. https://gitlab.cern.ch/atlas/athena/-/merge_requests/42889 Added a few Herwig7 ART tests https://gitlab.cern.ch/atlas/athena/-/merge_requests/42893 Patch xAODTauFilter.cxx to compile with HepMC3 https://gitlab.cern.ch/atlas/athena/-/merge_requests/42952 Added more Herwig7 ART tests https://gitlab.cern.ch/atlas/athena/-/merge_requests/42988 corrected the number of events generated https://gitlab.cern.ch/atlas/athena/-/merge_requests/43003 Sweeping !42977 from 21.6 to master. MGC tests, saving tgz outputs instead of event files https://gitlab.cern.ch/atlas/athena/-/merge_requests/43004 Sweeping !42973 from 21.6 to master. Making sure MGC cleans up copies of events