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.