Instead of linking the lib files to /usr/lib/ create a file libsodium.conf under /etc/ld.so.conf.d with the single line /usr/local/lib and run ldconfig once.
An alternative would be to run the ./configure command for the libsodium installation with '--prefix=/usr/lib/', however that would break the separation from apt-maintained libs and manually compiled libs.
Instead of linking the lib files to /usr/lib/ create a file libsodium.conf under /etc/ld.so.conf.d with the single line /usr/local/lib and run ldconfig once.
An alternative would be to run the ./configure command for the libsodium installation with '--prefix=/usr/lib/', however that would break the separation from apt-maintained libs and manually compiled libs.
It's a non-issue really as linking works.