Duplicate symbol from definition in function - c

Question

I am trying to define a global logger one time in a header file doing the following:
// log.c
#include <stdio.h>
#include "log.h"
void log_add_file(const char* filename)
{
printf("Adding file %s", filename);
}
void log_log(const char* filename, const char* function, int line, int level, ...)
{
printf("LOG");
}
// logmain.c
#include "log.h"
int main(void)
{
log_add_file("log.txt");
log_info("Hello");
}
#ifndef LOG_H
#define LOG_H
#include <stdio.h>
#define DEFAULT_FORMAT "[%(levelname)] %(time) %(name) - %(filename):%(funcName):%(lineno) - %(msg)"
enum LogLevel {
DEBUG=10,
INFO=20,
WARN=30,
ERROR=40,
};
struct logger {
int level;
const char* format;
FILE** handlers;
int num_handlers;
};
struct logger Logger = {INFO, DEFAULT_FORMAT, NULL, 1};
#define log_debug(...) log_log(__FILE__, __func__, __LINE__, DEBUG, __VA_ARGS__)
#define log_info(...) log_log(__FILE__, __func__, __LINE__, INFO , __VA_ARGS__)
#define log_warn(...) log_log(__FILE__, __func__, __LINE__, WARN , __VA_ARGS__)
#define log_error(...) log_log(__FILE__, __func__, __LINE__, ERROR , __VA_ARGS__)
void log_add_file(const char* filename);
void log_log(const char* filename, const char* function, int line, int level, ...);
#endif
The offending line is:
struct logger Logger = {INFO, DEFAULT_FORMAT, NULL, 1};
And the compiler says:
duplicate symbol _Logger____ in:
/var/folders/b1/mmc6r_jj00ldzr2prvqzy56m0000gp/T/log-9f31fa.o
/var/folders/b1/mmc6r_jj00ldzr2prvqzy56m0000gp/T/logmain-220d4d.o
ld: 1 duplicate symbol for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
What is the compiler saying in this case? First, why would a duplicate symbol matter here if logmain.c doesn't call log.c and vice versa? And secondly, what would be a way to resolve this?
Do I just add in the word static and call it a day? Or can that lead to other unintended consequences? Basically, I want all files to have the exact same Logger to use that includes it (a singleton).