fatal error: ../../libgloss/libnosys/config.h: No such file or directory

[Ocean276]

I build the Newlib cross-compiler, and i met this problem, i do not know how to solve this.
I typed the command like following
./configure --prefix=/opt/riscv
make

and the problem is:
/home/ysyx/xuantie-gnu-toolchain/riscv-newlib/newlib/libc/machine/riscv/pthread.c:7:10: fatal error: ../../libgloss/libnosys/config.h: No such file or directory
7 | #include "../../libgloss/libnosys/config.h"
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.
make[7]: *** [Makefile:343: lib_a-pthread.o] Error 1
make[7]: Leaving directory '/home/ysyx/xuantie-gnu-toolchain/build-newlib/riscv64-unknown-elf/newlib/libc/machine/riscv'
Making all in .
make[7]: Entering directory '/home/ysyx/xuantie-gnu-toolchain/build-newlib/riscv64-unknown-elf/newlib/libc/machine'
rm -f lib.a
ln riscv/lib.a lib.a >/dev/null 2>/dev/null ||
cp riscv/lib.a lib.a
cp: cannot stat 'riscv/lib.a': No such file or directory
make[7]: *** [Makefile:574: lib.a] Error 1
make[7]: Leaving directory '/home/ysyx/xuantie-gnu-toolchain/build-newlib/riscv64-unknown-elf/newlib/libc/machine'
make[6]: *** [Makefile:319: all-recursive] Error 1
make[6]: Leaving directory '/home/ysyx/xuantie-gnu-toolchain/build-newlib/riscv64-unknown-elf/newlib/libc/machine'
Making all in syscalls

thank you for your suggestions!!!