Building with solaris threads

[P.A.J.Saunders]

Im attempting to build gcc 3.1 with solaris threads, but during the build 
bohem-gc fails with 

checking for thread model used by GCC... solaris
configure: error: thread package solaris not yet supported
gnumake[2]: *** [configure-target-boehm-gc] Error 1
gnumake[2]: Leaving directory `/usr/local/src/net/gcc/3.1.0/build'
gnumake[1]: *** [bootstrap] Error 2
gnumake[1]: Leaving directory `/usr/local/src/net/gcc/3.1.0/build'
gnumake: *** [build] Error 2

Im configuring it with the flags 

--enable-languages=c++,java,f77 --enable-shared --enable-threads=solaris

I have successfully built gcc 3.0.4 with the same flags however. Am i doing 
something wrong, or has something changed i should be aware of?

Thanks

-- 
Pete