Error when compiling customer module, it says "cpu_set_t"

[crabvn]

I follow the steps on this doc
https://web.dev/how-to-set-up-signed-http-exchanges/#step-3-option-2
When I run make after config nginx-sxg-module it returns below error

-o objs/addon/nginx-sxg-module/ngx_sxg_utils.o \ ../nginx-sxg-module/ngx_sxg_utils.c In file included from src/os/unix/ngx_process.h:12, from src/core/ngx_core.h:55, from ../nginx-sxg-module/ngx_sxg_utils.c:20: src/os/unix/ngx_setaffinity.h:16:9: **error: unknown type name 'cpu_set_t'** 16 | typedef cpu_set_t ngx_cpuset_t; | ^~~~~~~~~ make[1]: *** [objs/Makefile:1234: objs/addon/nginx-sxg-module/ngx_sxg_utils.o] Error 1

I am using alpine:3.12 and nginx 1.19.2