You cannot really say that “you have a library on your system”. You have a certain version of a library, compiled with a certain set of compiler flags, with a certain set of RPATHs etc. By default, the package manager will install versions of packages built in such a way that they are compatible with the rest of the libraries. You can override this by pointing these libraries to local ones 8. Artifacts · Pkg.jl.
For some more info about artifacts, see:
and the JuliaCon talk
