LFS6.5第6.9章编译glibc出错

idn-stub.c: In function 'load_dso':
idn-stub.c:51: error: 'LIBCIDN_SO' undeclared (first use in this function)
idn-stub.c:51: error: (Each undeclared identifier is reported only once
idn-stub.c:51: error: for each function it appears in.)
make[2]: *** [/sources/glibc-build/libidn/idn-stub.o] Error 1
make[2]: Leaving directory `/sources/glibc-2.10.1/libidn'
make[1]: *** [libidn/subdir_lib] Error 2
make[1]: Leaving directory `/sources/glibc-2.10.1'
make: *** [all] Error 2