Does the Geany build build the libgdk DLL, or use a prebuilt or downloaded version?
It uses a pre-built one from the MSYS2 project. We do this because building GTK on windows isn't easy or fast. If you want to try, the instructions are on the GTK website but IIRC are for GTK3, not sure if they apply to GTK2.
@eht16 why doesn't windows build use GTK 3.22 now its "stable"?