cp /boot/common/share/libtool/config/config.* ./mk/libtool/ (libtoolize doesn't work here)
./configure --prefix=common (first time do this to create libtool)
cp /boot/common/share/libtool/config/ltmain.sh ./mk/libtool/
    needed to do this otherwise libtool was not created
run configure again

edit ./gui/units.c + ./include/agar/math/m_line.h (undeclared HUGE_VAL)
add:

{{{
    #if (defined(__BEOS__) || defined(__HAIKU__))
    #include <math.h> /* declares HUGE_VAL */
    #endif

}}}

make
make install

(does not seem to build/create shared libs)