[Mac OS X 10.4.11] ruby1.9-trunk make failed

on Mac OS X 10.4.11 the ruby1.9-trunk make failed with the following :

~/work/Ruby/ruby1.9-trunk%> make
gcc -g -O2 -pipe -fno-common  -I. -I.ext/include/powerpc-darwin8.11.0
-I./include -I.  -DRUBY_EXPORT  -c main.c
[...]
gcc -g -O2 -pipe -fno-common  -I. -I.ext/include/powerpc-darwin8.11.0
-I./include -I.  -DRUBY_EXPORT  -c pack.c
bison  -o y.tab.c parse.y
parse.y:580: non reconnu: %parse_param    #(not recognize %parse_para)
parse.y:580:    Saut jusqu'au prochain %  #(jump to next %)
make: *** [parse.c] Error 1
~

is it a known prob? I'd like to make a try of 1.9...
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