@User Okay, partial victory. Since all the errors were warnings about implicit function declaration, I used this string in the CFLAGS in defs.mak: -Wno-error=implicit-function-declaration That converted the errors back into warnings, and the object files were created. However, make did stop prematurely: --- linking libtcltk.o --- compiling magic/magicTop.o magicTop.c535: warning: implicit declaration of function 'magicMain' [-Wimplicit-function-declaration] --- linking libmagic.o --- making Tcl shared libraries make[2]: * No rule to make target `../extract/libextract.o', needed by `tclmagic.dylib'. Stop. bash-3.2$