shl_ref is missing

[pcotret]

I'm using the Docker image given in one of T-Head tutorial. Once I've fixed the C906 path in the example, I have an error with the shl_ref header file.

root@f562828a54da:/home/example/manip_pascal/csi-nn2/example# make
riscv64-unknown-linux-gnu-gcc c906_mobilenetv1_f16.c -o c906_mobilenetv1_f16.elf -I../include ../install_nn2/c906/lib/libshl_c906.a -lm -static
c906_mobilenetv1_f16.c:19:10: fatal error: shl_ref.h: No such file or directory
   19 | #include <shl_ref.h>
      |          ^~~~~~~~~~~