#18 Build error on Arch Linux system

Hi,
building ggmud on Arch Linux ends with the below error message. Any idea where the problem might be?

Following sw is used to build the package in clean chroot:
atk-2.12.0-1 avahi-0.6.31-13 cairo-1.12.16-3 compositeproto-0.4.2-3 damageproto-1.2.1-3 dbus-1.8.6-1 elfutils-0.159-1 fixesproto-5.0-3 fontconfig-2.11.1-1 freetype2-2.5.3-2 gdk-pixbuf2-2.30.8-1 graphite-1:1.2.4-1 gtk-update-icon-cache-2.24.24-1 harfbuzz-0.9.35-1 hicolor-icon-theme-0.13-1 hwids-20140602-1 inputproto-2.3.1-1 jasper-1.900.1-10 kbd-2.0.2-1 kbproto-1.0.6-2 kmod-18-1 libcups-1.7.5-1 libdaemon-0.14-3 libdatrie-0.2.6-1 libdbus-1.8.6-1 libdrm-2.4.56-1 libjpeg-turbo-1.3.1-1 libpciaccess-0.13.2-2 libpng-1.6.12-1 libseccomp-2.1.1-1 libthai-0.1.19-1 libtiff-4.0.3-4 libx11-1.6.2-2libxau-1.0.8-2 libxcb-1.11-1 libxcomposite-0.4.4-2 libxcursor-1.1.14-2 libxdamage-1.1.4-2 libxdmcp-1.1.1-2 libxext-1.3.3-1 libxfixes-5.0.1-1 libxft-2.3.2-1 libxi-1.7.4-1 libxinerama-1.1.3-2 libxml2-2.9.1-5 libxrandr-1.4.2-2 libxrender-0.9.8-1 libxshmfence-1.1-1 libxxf86vm-1.1.3-1 llvm-libs-3.4.2-1 mesa-10.2.7-1 mesa-libgl-10.2.7-1 pango-1.36.6-1 pixman-0.32.6-1 randrproto-1.4.0-2 renderproto-0.11.1-3 shared-mime-info-1.3-1 systemd-216-3 wayland-1.5.0-1 xcb-proto-1.11-1 xextproto-7.3.0-1 xf86vidmodeproto-2.3.1-3 xineramaproto-1.2.1-3 xproto-7.0.26-1 gtk2-2.24.24-1 cmake-3.0.1-1

ERROR MESSAGE:
...
[ 95%] Building C object CMakeFiles/ggmud.dir/pixmaps.c.o
[ 96%] Building C object CMakeFiles/ggmud.dir/buttons.c.o
[ 97%] Building C object CMakeFiles/ggmud.dir/autoupdate.c.o
[ 98%] Building C object CMakeFiles/ggmud.dir/msp.c.o
[ 99%] Building C object CMakeFiles/ggmud.dir/chat.c.o
[100%] Building C object CMakeFiles/ggmud.dir/sub.c.o
Linking C executable ggmud
/usr/bin/ld: lua/liblua.a(lmathlib.c.o): undefined reference to symbol 'fmod@@GLIBC_2.2.5'
/usr/lib/libm.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
CMakeFiles/ggmud.dir/build.make:890: recipe for target 'ggmud' failed
make[2]: *** [ggmud] Error 1
CMakeFiles/Makefile2:64: recipe for target 'CMakeFiles/ggmud.dir/all' failed
make[1]: *** [CMakeFiles/ggmud.dir/all] Error 2
Makefile:76: recipe for target 'all' failed
make: *** [all] Error 2