Code example:
---------------8<--------------------
#define LOG(args...) fprintf(stderr, ## args)
int foo(char * env_map, char * env_log) {
    LOG("\n>>>NBBUILD: TOOLS=%s\n\tLOG=%s\n", env_map, env_log);
}
---------------8<--------------------
Actual expansion is:

int foo(char * env_map, char * env_log) {
    fprintf(stderr ,"\n>>>NBBUILD: TOOLS=%s\n\tLOG=%s\n" );
}

Expected expansion is:

int foo(char * env_map, char * env_log) {
    fprintf(stderr ,"\n>>>NBBUILD: TOOLS=%s\n\tLOG=%s\n", env_map, env_log);
}