cannot find find_btf_id symbol in libbpf.c.o

[baiwfg2]

I build v0.28.0 successfully, but find a strange issue. I pick some function symbol and look for them in libbpf.c.o(source file is src/cc/libbpf.c). I can find all symbol except find_btf_id. Why ?

# nm bld/src/cc/CMakeFiles/bpf-static.dir/libbpf.c.o | egrep 'find_btf_id|bcc_prog_load_xattr|bpf_open_raw_sock|libbpf_bpf_prog_load|bpf_prog_get_tag|bpf_attach_socket'
0000000000001a50 T bcc_prog_load_xattr
0000000000002a60 T bpf_attach_socket
0000000000002940 T bpf_open_raw_sock
0000000000001980 T bpf_prog_get_tag
0000000000000000 t libbpf_bpf_prog_load

# nm bld/src/cc/CMakeFiles/bpf-shared.dir/libbpf.c.o | egrep 'find_btf_id|bcc_prog_load_xattr|bpf_open_raw_sock|libbpf_bpf_prog_load|bpf_prog_get_tag|bpf_attach_socket'
0000000000001a50 T bcc_prog_load_xattr
0000000000002a60 T bpf_attach_socket
0000000000002940 T bpf_open_raw_sock
0000000000001980 T bpf_prog_get_tag
0000000000000000 t libbpf_bpf_prog_load

[yonghong-song]

find_btf_id is a static function. It may have been inlined.