cannot link with gtk though all flags look good

[ghost]

Ubuntu 19.

machine:~/APPS/waon-0.8$ make gwaon
gcc -Wall -O3 -ffast-math -I/usr/include/glib-2.0 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/atk-1.0 -I/usr/include/gtk-3.0 -I/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/include/cairo -I/usr/include/pango-1.0 `pkg-config --cflags fftw3` `pkg-config --cflags sndfile`  -L/usr/local/lib -L/usr/lib/x86_64-linux-gnu `pkg-config --cflags --libs gtk+-3.0` `pkg-config --libs fftw3` `pkg-config --libs sndfile` -lm   gwaon.c   -o gwaon
/usr/bin/ld: /tmp/ccI6JHjC.o: in function `main':
gwaon.c:(.text.startup+0x15): undefined reference to `gtk_init'
/usr/bin/ld: gwaon.c:(.text.startup+0x1a): undefined reference to `create_menu'
/usr/bin/ld: gwaon.c:(.text.startup+0x1f): undefined reference to `gtk_main'
collect2: error: ld returned 1 exit status
make: *** [<builtin>: gwaon] Error 1

where the pkg-config --cflags --libs gtk+-3.0 looks like

machine:~/APPS/waon-0.8$ pkg-config --cflags --libs gtk+-3.0
-pthread -I/usr/include/gtk-3.0 -I/usr/include/at-spi2-atk/2.0 -I/usr/include/at-spi-2.0 -I/usr/include/dbus-1.0 -I/usr/lib/x86_64-linux-gnu/dbus-1.0/include -I/usr/include/gtk-3.0 -I/usr/include/gio-unix-2.0 -I/usr/include/cairo -I/usr/include/libdrm -I/usr/include/pango-1.0 -I/usr/include/harfbuzz -I/usr/include/pango-1.0 -I/usr/include/fribidi -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng16 -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/libmount -I/usr/include/blkid -I/usr/include/uuid -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -lgtk-3 -lgdk-3 -lpangocairo-1.0 -lpango-1.0 -latk-1.0 -lcairo-gobject -lcairo -lgdk_pixbuf-2.0 -lgio-2.0 -lgobject-2.0 -lglib-2.0

and ldd looks ok

marius@bsmt:/usr/lib/x86_64-linux-gnu$ ldd libgtk-3.so
	linux-vdso.so.1 (0x00007ffc40328000)
	libgdk-3.so.0 => /lib/x86_64-linux-gnu/libgdk-3.so.0 (0x00007f2284b39000)
	libgmodule-2.0.so.0 => /lib/x86_64-linux-gnu/libgmodule-2.0.so.0 (0x00007f2284b33000)
	libpangocairo-1.0.so.0 => /lib/x86_64-linux-gnu/libpangocairo-1.0.so.0 (0x00007f2284b23000)
	libX11.so.6 => /lib/x86_64-linux-gnu/libX11.so.6 (0x00007f22849e9000)
	libXi.so.6 => /lib/x86_64-linux-gnu/libXi.so.6 (0x00007f22847d9000)
	libXfixes.so.3 => /lib/x86_64-linux-gnu/libXfixes.so.3 (0x00007f22845d3000)
	libcairo-gobject.so.2 => /lib/x86_64-linux-gnu/libcairo-gobject.so.2 (0x00007f22845c5000)
	libcairo.so.2 => /lib/x86_64-linux-gnu/libcairo.so.2 (0x00007f22844a5000)
	libgdk_pixbuf-2.0.so.0 => /lib/x86_64-linux-gnu/libgdk_pixbuf-2.0.so.0 (0x00007f228447f000)
	libatk-1.0.so.0 => /lib/x86_64-linux-gnu/libatk-1.0.so.0 (0x00007f2284456000)
	libatk-bridge-2.0.so.0 => /lib/x86_64-linux-gnu/libatk-bridge-2.0.so.0 (0x00007f2284422000)
	libepoxy.so.0 => /lib/x86_64-linux-gnu/libepoxy.so.0 (0x00007f22842f0000)
	libfribidi.so.0 => /lib/x86_64-linux-gnu/libfribidi.so.0 (0x00007f22842d1000)
	libgio-2.0.so.0 => /lib/x86_64-linux-gnu/libgio-2.0.so.0 (0x00007f2284108000)
	libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f2283fba000)
	libharfbuzz.so.0 => /lib/x86_64-linux-gnu/libharfbuzz.so.0 (0x00007f2283ec1000)
	libpangoft2-1.0.so.0 => /lib/x86_64-linux-gnu/libpangoft2-1.0.so.0 (0x00007f2283ea8000)
	libpango-1.0.so.0 => /lib/x86_64-linux-gnu/libpango-1.0.so.0 (0x00007f2283e5d000)
	libgobject-2.0.so.0 => /lib/x86_64-linux-gnu/libgobject-2.0.so.0 (0x00007f2283dff000)
	libglib-2.0.so.0 => /lib/x86_64-linux-gnu/libglib-2.0.so.0 (0x00007f2283cde000)
	libfontconfig.so.1 => /lib/x86_64-linux-gnu/libfontconfig.so.1 (0x00007f2283c98000)
	libfreetype.so.6 => /lib/x86_64-linux-gnu/libfreetype.so.6 (0x00007f2283bdd000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007f2283bbc000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f22839d1000)
	libXinerama.so.1 => /lib/x86_64-linux-gnu/libXinerama.so.1 (0x00007f22839ca000)
	libXrandr.so.2 => /lib/x86_64-linux-gnu/libXrandr.so.2 (0x00007f22837bf000)
	libXcursor.so.1 => /lib/x86_64-linux-gnu/libXcursor.so.1 (0x00007f22837b4000)
	libXcomposite.so.1 => /lib/x86_64-linux-gnu/libXcomposite.so.1 (0x00007f22835b1000)
	libXdamage.so.1 => /lib/x86_64-linux-gnu/libXdamage.so.1 (0x00007f22833ae000)
	libxkbcommon.so.0 => /lib/x86_64-linux-gnu/libxkbcommon.so.0 (0x00007f228336d000)
	libwayland-cursor.so.0 => /lib/x86_64-linux-gnu/libwayland-cursor.so.0 (0x00007f2283362000)
	libwayland-egl.so.1 => /lib/x86_64-linux-gnu/libwayland-egl.so.1 (0x00007f228335d000)
	libwayland-client.so.0 => /lib/x86_64-linux-gnu/libwayland-client.so.0 (0x00007f228334c000)
	libXext.so.6 => /lib/x86_64-linux-gnu/libXext.so.6 (0x00007f228313a000)
	librt.so.1 => /lib/x86_64-linux-gnu/librt.so.1 (0x00007f228312f000)
	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f2283129000)
	libxcb.so.1 => /lib/x86_64-linux-gnu/libxcb.so.1 (0x00007f22830fe000)
	libpixman-1.so.0 => /lib/x86_64-linux-gnu/libpixman-1.so.0 (0x00007f2283058000)
	libpng16.so.16 => /lib/x86_64-linux-gnu/libpng16.so.16 (0x00007f2283021000)
	libxcb-shm.so.0 => /lib/x86_64-linux-gnu/libxcb-shm.so.0 (0x00007f228301c000)
	libxcb-render.so.0 => /lib/x86_64-linux-gnu/libxcb-render.so.0 (0x00007f228300d000)
	libXrender.so.1 => /lib/x86_64-linux-gnu/libXrender.so.1 (0x00007f2282e01000)
	libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f2282de5000)
	libdbus-1.so.3 => /lib/x86_64-linux-gnu/libdbus-1.so.3 (0x00007f2282d96000)
	libatspi.so.0 => /lib/x86_64-linux-gnu/libatspi.so.0 (0x00007f2282d63000)
	libmount.so.1 => /lib/x86_64-linux-gnu/libmount.so.1 (0x00007f2282d07000)
	libselinux.so.1 => /lib/x86_64-linux-gnu/libselinux.so.1 (0x00007f2282cdb000)
	libresolv.so.2 => /lib/x86_64-linux-gnu/libresolv.so.2 (0x00007f2282cc0000)
	/lib64/ld-linux-x86-64.so.2 (0x00007f2285358000)
	libgraphite2.so.3 => /lib/x86_64-linux-gnu/libgraphite2.so.3 (0x00007f2282c93000)
	libthai.so.0 => /lib/x86_64-linux-gnu/libthai.so.0 (0x00007f2282c88000)
	libffi.so.6 => /lib/x86_64-linux-gnu/libffi.so.6 (0x00007f2282c7e000)
	libpcre.so.3 => /lib/x86_64-linux-gnu/libpcre.so.3 (0x00007f2282c08000)
	libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1 (0x00007f2282bcb000)
	libuuid.so.1 => /lib/x86_64-linux-gnu/libuuid.so.1 (0x00007f2282bc2000)
	libXau.so.6 => /lib/x86_64-linux-gnu/libXau.so.6 (0x00007f22829be000)
	libXdmcp.so.6 => /lib/x86_64-linux-gnu/libXdmcp.so.6 (0x00007f22827b8000)
	libsystemd.so.0 => /lib/x86_64-linux-gnu/libsystemd.so.0 (0x00007f2282718000)
	libblkid.so.1 => /lib/x86_64-linux-gnu/libblkid.so.1 (0x00007f22826c3000)
	libdatrie.so.1 => /lib/x86_64-linux-gnu/libdatrie.so.1 (0x00007f22826ba000)
	libbsd.so.0 => /lib/x86_64-linux-gnu/libbsd.so.0 (0x00007f22826a0000)
	liblzma.so.5 => /lib/x86_64-linux-gnu/liblzma.so.5 (0x00007f2282679000)
	liblz4.so.1 => /lib/x86_64-linux-gnu/liblz4.so.1 (0x00007f2282648000)
	libgcrypt.so.20 => /lib/x86_64-linux-gnu/libgcrypt.so.20 (0x00007f228252a000)
	libgpg-error.so.0 => /lib/x86_64-linux-gnu/libgpg-error.so.0 (0x00007f2282507000)

[ildar]

https://duckduckgo.com/?q=link+as-needed