/home/mhough/Downloads/SimpleITK-build/ITK/Modules/ThirdParty/VNL/src/vxl/vcl/vcl_compiler.h:101:4: error: #error “Dunno about this gcc”
101 | # error “Dunno about this gcc”
Adding an additional elseif for GCC9 fixes this. I am afraid I am not sure which repo I should try and update for this problem. It seems to be an ITK 4.x problem. Thanks in advance for your time.