This Julia package is used to set shared library installation preferences for ROOT.jl. Preferences must be set before the ROOT module is imported, which is why methods for setting them are provided in a separate package.
ROOT.jl offers a Julia interface to the C++ ROOT framework. This package requires the C++ ROOT shared libraries and a shared library that provides the Julia bindings based on CxxWrap.
The ROOT_jll and ROOT_julia_jll packages, which are installed by the Julia package manager when adding ROOT.jl, provide the shared libraries for Linux. An alternative option, currently the only one available on macOS, is to use a standard ROOT C++ software installation (not ROOT_jll). In this case, the C++-Julia interface shared library is built on-the-fly the first time the ROOT module is imported.
The ROOTprefs Julia package offers methods to customize how the C++ shared libraries are provided. In particular, see the use_root_jll!(enable=true) and set_ROOTSYS!(ROOTSYS) methods. Preferences are stored in the LocalPreferences.toml file of the active Julia project.