No clue why this: pkg-config proj –libs gives: -lproj when it should be: -L/usr/lib/x86_64-linux-gnu -lproj because proj.pc is in /usr/lib/x86_64-linux-gnu/pkgconfig/ Now, is this problem related to proj_api.h not found in standard or given locations? My LMint 20.1 does not find that. I keep getting: Even though proj_api.h is here: Is this a problem with PROJ4 version 7.2.1-1? I found some