CMake Error at clad-stamp/clad-download-Release.cmake:49 (message):

ROOT
2

Please post the actual error from the log file CMake indicates:

See also:
/home/seanmeredith/Programs/build-root/interpreter/llvm/src/tools/cling/tools/plugins/clad/clad-prefix/src/clad-stamp/clad-download-*.log