With this patch, when a user install a package using Julia package manager, the package manager finds packages that were already installed in the guix profile and use them. First patch of the serie does the implementation, the second patch is an example using sundials_jll package. Sundials_jll is a julia package that wraps the sundials library, it is typically not installed on its own but as a dependency of DifferentialEquations.jl for example. As DifferentialEquations.jl is not currently packaged in julia, a fallback is to install it with julia package manager. Unfortunately that will also install sundials_jll and downloads some .so that will fail to load on Guix because of linker incompatilibities. Now with the proposed patch, the user can install sundials_jll using guix, and then julia package manager will use this package instead of downloading some binary files. As for the patch itself, it works by following more closely the directory structure that Julia expects in JULIA_DEPOT_PATH. Namely the packages subfolder should not contain packages but packages/XXXX/ where XXXX is a string encoding package uuid and sha1 of package files. $JULIA_DEPOT_PATH/packages was also used as JULIA_LOAD_PATH, this will not work anymore as packages are behind a layer of XXXX sub directories. So instead I added a new subfolder $JULIA_DEPOT_PATH/loadpath where the package is installed and $JULIA_DEPOT_PATH/packages/XXXX is a symlink to it. Jean-Baptiste Volatier (2): build-system/julia: Enable Julia Pkg to find installed packages gnu: Add julia-sundials-jull gnu/packages/julia-jll.scm | 38 +++++++++++++++++++++++++ gnu/packages/julia-xyz.scm | 2 +- gnu/packages/julia.scm | 2 +- gnu/packages/maths.scm | 24 ++++++++++++++++ guix/build/julia-build-system.scm | 46 ++++++++++++++++++++++++++++--- 5 files changed, 106 insertions(+), 6 deletions(-) -- 2.33.1