Error while compiling colorpicker.c on macOS

[rafi]

NVIM v0.2.0-989-g6fbcbeba
OS: macOS 10.12.4

$  make
gcc -g -Wall -o colorpicker colorpicker.c -export-dynamic `pkg-config --cflags --libs gtk+-2.0`
Undefined symbols for architecture x86_64:
  "xport-dynamic", referenced from:
     implicit entry/start for main executable
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [main] Error 1

gtk2 is installed:

$ pkg-config --cflags --libs gtk+-2.0
-D_REENTRANT -I/opt/local/include/gtk-2.0 -I/opt/local/lib/gtk-2.0/include -I/opt/local/include/pango-1.0 -I/opt/local/include/gio-unix-2.0/ -I/opt/local/include -I/opt/local/include/cairo -I/opt/local/include/atk-1.0 -I/opt/local/include/cairo -I/opt/local/include/pixman-1 -I/opt/local/include/libpng16 -I/opt/local/include -I/opt/local/include/gdk-pixbuf-2.0 -I/opt/local/include/libpng16 -I/opt/local/include/pango-1.0 -I/opt/local/include/harfbuzz -I/opt/local/include -I/opt/local/include/pango-1.0 -I/opt/local/include/glib-2.0 -I/opt/local/lib/glib-2.0/include -I/opt/local/include -I/opt/local/include/freetype2 -I/opt/local/include -I/opt/local/include/freetype2 -L/opt/local/lib -lgtk-x11-2.0 -lgdk-x11-2.0 -lpangocairo-1.0 -lgio-2.0 -lXrender -lXinerama -lXi -lXrandr -lXcursor -lXcomposite -lXdamage -lXfixes -lX11 -lXext -latk-1.0 -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lpangoft2-1.0 -lpango-1.0 -lgobject-2.0 -lglib-2.0 -lintl -lfontconfig -lfreetype

[gu-fan]

well... I have not tested on mac...

And it's long time unmaintained.
I don't have time for this now...

you may try pick color hex with other app. Thanks~