[same as prefix]
--enable-threads=TYPE choose threading package
--enable-parallel-mark parallelize marking and free list construction
- --enable-full-debug include full support for pointer backtracing etc.
+ --enable-gc-debug (--enable-full-debug before about 7.0)
+ include full support for pointer backtracing etc.
+
Unless --prefix is set (or --exec-prefix or one of the more obscure options),
make install will install libgc.a and libgc.so in /usr/local/bin, which