I compiled davix 0.7.1 and installed it into /opt/davix
When I use cmake to install ROOT 6.16, I systematically get this message
No package ‘davix’ found
I tried to add /opt/davix/lib64 in my .bashrc (LD_LIBRARY_PATH variable) but it does not help.
So I guess that ROOT looks for davix.pc, that is located in /opt/davix/lib64/pkgconfig, but I have no idea how to tell to cmake that this file is located there.
Davix is a bit annoying in that it only exports its version (which we need to check) in the .pc file. Due to that we look for it with pkg-config (via its CMake module) instead of parsing the header and using find_library(). Please try also with -DCMAKE_PREFIX_PATH=/opt/davix and let me know if that works. This is the standard way of giving extra search paths to CMake.