Package xcb-shm was not found in the pkg-config search path

I tried running a hello world program in GTK from the official tutorial page

They basically say:

clang++ `pkg-config --cflags gtk+-2.0` hello.cpp `pkg-config --libs gtk+-2.0` -o hello

This assumes that gtk is installed (brew install gtk+). Also for easiness, they recommend to use pkg-config to get the entire list of paths to compile something that uses gtk.

The problem is that pkg-config complains about "xcv-shm blah blah blah" and it does not work.

The answer from here is to set PKG_CONFIG_PATH appropriately. Apparently is a miss configuration of gtk + x11 + brew.

$ pkg-config --cflags gtk+-2.0
Package xcb-shm was not found in the pkg-config search path.
Perhaps you should add the directory containing `xcb-shm.pc'
to the PKG_CONFIG_PATH environment variable
Package 'xcb-shm', required by 'cairo', not found

PKG_CONFIG_PATH should be set so it reads from Xquartz path so we need to add it to ~/.profile.

$ echo "export PKG_CONFIG_PATH=/opt/X11/lib/pkgconfig" >> ~/.profile

Now it works :)

$ pkg-config --cflags gtk+-2.0
-D_REENTRANT -I/opt/X11/include/cairo -I/opt/X11/include/pixman-1 -I/opt/X11/include/libpng15 -I/opt/X11/include -I/opt/X11/include/libpng15 -I/opt/X11/include -I/opt/X11/include/freetype2 -I/opt/X11/include -I/opt/X11/include/freetype2 -I/opt/X11/include -I/usr/local/Cellar/gtk+/2.24.22/include/gtk-2.0 -I/usr/local/Cellar/gtk+/2.24.22/lib/gtk-2.0/include -I/usr/local/Cellar/pango/1.36.1/include/pango-1.0 -I/usr/local/Cellar/atk/2.10.0/include/atk-1.0 -I/usr/local/Cellar/gdk-pixbuf/2.30.1/include/gdk-pixbuf-2.0 -I/usr/local/Cellar/pango/1.36.1/include/pango-1.0 -I/usr/local/Cellar/harfbuzz/0.9.25/include/harfbuzz -I/usr/local/Cellar/pango/1.36.1/include/pango-1.0 -I/usr/local/Cellar/glib/2.38.2/include/glib-2.0 -I/usr/local/Cellar/glib/2.38.2/lib/glib-2.0/include -I/usr/local/opt/gettext/include