Yep, oddly the conflicting proj libraries doesn’t seem to cause problem on ubuntu. I updated my opensuse 15.1 docker file to build OTB using only PROJ 6.2 :
Dockerfile (2.2 KB)
You also had to compile a more recent geotiff lib right ?
At some point we should upgrade gdal to 3.X in the Superbuild (and proj to proj 6.X), this will make things easier.