This is a standalone version of the ROOT EGPythia6 library, which was removed in ROOT v6.30.
The src/ and inc/ directories are copied from the ROOT source tree at version 6.28.00.
git clone https://github.com/luketpickering/ROOTEGPythia6.git
cd ROOTEGPythia6; mkdir build; cd build
cmake .. -DROOTEGPythia6_Pythia6_BUILTIN=<ON|OFF>
make install #installs to ROOTEGPythia6/build/Linux/ by defaultFirst add the build location to the CMake prefix path
export ROOTEGPythia6_ROOT=/path/to/ROOTEGPythia6/build/Linuxfind_package(ROOTEGPythia6 REQUIRED)
target_link_libraries(tgt PUBLIC ROOT::EGPythia6)gcc ... `${ROOTEGPythia6_ROOT}/bin/ROOTEGPythia6-config --cxxflags` ...
gcc ... `${ROOTEGPythia6_ROOT}/bin/ROOTEGPythia6-config --ldflags` ...