Hi @Mahvin , the tgz files from @Carmelo_DrRaw don’t need the MacPorts environment!
After installing gmic-qt with MacPorts (and possibly but not necessarily using Gimp from MacPorts) I had since inclusion of gmic into MacPorts never more any problems! The crucial point is IMHO the installation of MacPorts! Still the differences of gmic 2.9.7 and 2.9.8 are so large, possibly a new version might help.
By the way, with the latest git from gmic (2.9.8), gmic-qt and zart the following commands build successful on my Mac (OS 11.4) :
make -B CXX=clang++ OPENCV_CFLAGS="\$(shell pkg-config opencv4 --cflags)" OPENCV_LIBS="\$(shell pkg-config opencv4 --libs)" EXTRA_CFLAGS="-march=native -O3 -flto -Wno-c11-extensions -Wno-deprecated-declarations -Dcimg_use_opencv $(OPENCV_CFLAGS) -Dcimg_use_heif" EXTRA_LIBS="$(OPENCV_LIBS) -lheif" cli
make -B gimp gmic_qt zart “SUBLIBS=-lX11”