On Saturday, 16 February 2019 at 13:35:57 UTC, Ron Tarrant wrote:
dmd -de -w -m64 -L+gtkd hello_gtkd_world.d
DMD's -L switch means "pass the following flag to the linker". Linker arguments are system-dependent. The + is what you use on Windows to specify the library path when running DMD with the default 32-bit linker (optlink). On Linux, it's actually -L, so you should be specifying -L-Lgtkd.
Assuming, of course, gtkd is the path and not the library name.