getaddrinfo bind: Address already in use - c++

Question

Whenever I attempt to run my app on macOS Catalina 10.15.2 (19C57) or Linux 5.4.3-arch1-1 x86_64 GNU/Linux, I get:
_rSockd: bind: Address already in use
libc++abi.dylib: terminating with uncaught exception of type std::runtime_error: failed to bind to socket
[1] 31181 abort Saol/saol
Now I have checked for open ports with sudo netstat -tulp udp and sudo lsof -i udp, but none of these report any applications of mine using these ports. Nothing is currently listening on the port(45100).
I have browsed several similar posts that mentioned adding the SO_REUSEADDR, but this did not change anything when I have it or when I don't.
Posts also mentioned checking for something using the port, but I was unable (I believe unless the above commands were the wrong ones to use) to find my ports locked up. I have tried several different ports(currently using 45100); the _port var is set to an int before the _Init function is called. getaddrinfo's second argument is a const char *service, and stated in the man pages:
service sets the port in each returned address structure. If this
argument is a service name (see services(5)), it is translated to the
corresponding port number. This argument can also be specified as a
decimal number, which is simply converted to binary. If service is
NULL, then the port number of the returned socket addresses will be
left uninitialized. If AI_NUMERICSERV is specified in hints.ai_flags
and service is not NULL, then service must point to a string contain‐
ing a numeric port number. This flag is used to inhibit the invoca‐
tion of a name resolution service in cases where it is known not to
be required.
All I am doing to the _port is this: int -> string -> char *
Below is the relevant section of my code:
#include <iostream>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <unistd.h>
#define PORT "45100"
auto main(void) -> int {
int rv;
int _rSockd;
const char * port = std::to_string(8080).c_str();
struct addrinfo hints;
struct addrinfo *servinfo;
struct addrinfo *p;
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_flags = AI_PASSIVE;
if((rv = getaddrinfo(NULL, port, &hints, &servinfo)) != 0) {
std::cerr << "getaddrinfo: " << std::endl << gai_strerror(rv) << std::endl;
throw std::runtime_error("failed to getaddrinfo");
}
for(p = servinfo; p != NULL; p = p->ai_next) {
if((_rSockd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1) {
std::perror("_rSockd: socket");
close(_rSockd);
continue;
}
if(bind(_rSockd, p->ai_addr, p->ai_addrlen) == -1) {
close(_rSockd);
std::perror("_rSockd: bind");
continue;
}
break;
}
if(p == NULL) {
throw std::runtime_error("failed to bind to socket");
}
freeaddrinfo(servinfo);
return 0;
}
Any help would be appreciated; I feel I have been staring at it too long and am missing something basic.
NOTE: When I added the MCVE (the above updated code), I no longer have my issue when running with port 8080 and 45100. So I will now explain the ??build?? process now to see if this is causing the issue.
UPDATE
When I made the MCVE, it worked. It never had the issues from my project base.
My project is a library being called from another executable project. libSaol has the netcode, saol is the executable that links libSaol.
To be honest, this confuses me more...