>htslib.c:2668: error: invalid operands to binary -

Darn! "timezone" does not seems to be declared.

Can you try to inset the following lines in htslib.c, around line 2668, just
before "return (time_t) (t - timezone);" please ? :

#ifdef BSD
    time_t now = time(NULL); 
    time_t timezone = - localtime(&now)->tm_gmtoff;
#endif

That is (full 'getGMT' function):

static time_t getGMT(struct tm *tm) {		/* hey, time_t is local! */
	time_t t = mktime(tm);
	if (t != (time_t) -1 && t != (time_t) 0) {
#ifdef BSD
    time_t now = time(NULL); 
    time_t timezone = - localtime(&now)->tm_gmtoff;
#endif
    return (time_t) (t - timezone);
	}
	return (time_t) -1;
}

And tell me if this is okay now ?
You'll also have to copy/paste the same function in src/proxy/store.c, around
line 1829