Building ROOT

In the pCT project we need to use a version of ROOT which is compiled with c++17 in order to build packages with ROOT dependencies with c++17 standard. .

ROOT implements a custom adaptor to std::string_view if not compiled with c++17 and this conflicts with the real one if a packages uses c++17 standard and ROOT libraries/includes.

# clone the repository
git clone http://github.com/root-project/root.git

# choose a build directory
mkdir build_root; cd build_root

# configure: choose install target, on the lab machine we need to disable asimage for some reason
# the important flag is the C++ standard
cmake -D CMAKE_INSTALL_PREFIX=/opt/root -D asimage=OFF -D CMAKE_CXX_STANDARD=17 ../root

#build
make -j

# install (eventually using sudo)
make install