Getting "Problem with the SSL CA cert" error while using libcurl

Question

I've built openssl 1.1.1 with --openssldir=< path to ssl >/ssl (link to /etc/ssl) and curl 7.76.1 with --with-ssl=< path to openssl >. Compiled the following code:

#include <iostream>
#include <curl/curl.h>

int main()
{
    CURL *curl = curl_easy_init();
    if (curl)
    {       
        struct curl_slist *headers = NULL;
        headers = curl_slist_append(headers, "Accept: */*");
        headers = curl_slist_append(headers, "Content-Type: application/json");

        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
        curl_easy_setopt(curl, CURLOPT_URL, "https://<address>");
        curl_easy_setopt(curl, CURLOPT_POST, 1);

        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "<some data>");
    
        curl_easy_perform(curl);
    
        curl_slist_free_all(headers)
    }
    curl_easy_cleanup(curl);
}

When I'm running this code I get an error:

curl_easy_operation() failed : Problem with the SSL CA cert (path? access rights?)

I see in strace, that it's trying to open "/etc/pki/tls/certs/ca-bundle.crt" But in my machines (Ubuntu 12 and Ubuntu 14) there is no folder "/etc/pki". Why does curl use "/etc/pki" instead of "/etc/ssl"? How can I force it do use "/etc/ssl"? I tried to build curl with --without-nss, but it didn't work.

EDIT: My solution was adding this code:

ifstream caBundleFile("/etc/pki/tls/certs/ca-bundle.crt");
if (caBundleFile.good()) {
    curl_easy_setopt(curl, CURLOPT_CAINFO, "/etc/pki/tls/certs/ca-bundle.crt");
    caBundleFile.close();
} else {
    curl_easy_setopt(curl, CURLOPT_CAPATH, "/etc/ssl/certs");
}

There are two popular formats of storing root certificates. First one is for RHEL/Centos like, and second is for Ubuntu like distros.