ngx_http_geoip2_module: ‘struct crypt_data’ has no member named ‘current_salt’

I'm installing GeoIP Module pre-requisites on my DigitalOcean Droplet (nginx/ubuntu) and I encountered this problem when I type in make command.

src/os/unix/ngx_user.c: In function ‘ngx_libc_crypt’:
src/os/unix/ngx_user.c:26:7: error: ‘struct crypt_data’ has no member named ‘current_salt’
   26 |     cd.current_salt[0] = ~salt[0];
      |       ^
make[1]: *** [objs/Makefile:784: objs/src/os/unix/ngx_user.o] Error 1
make[1]: Leaving directory '/usr/local/src/nginx-1.13.12'
make: *** [Makefile:8: build] Error 2

Command executed before make was ./configure --add-dynamic-module=/root/ngx_http_geoip2_module.

I already performed sudo apt-get update and sudo apt-get upgrade as a trial and error to fix the problem, and no luck.

How to fix the issue? Thank you! 😢

leev / ngx_http_geoip2_module

ngx_http_geoip2_module: ‘struct crypt_data’ has no member named ‘current_salt’ #101