Conditionally include epoll headers.
#include <signal.h>
#include <sys/ioctl.h>
#include <sys/types.h>
-#include <sys/epoll.h>
#include <fcntl.h>
+
+#ifdef JANET_EV_EPOLL
+#include <sys/epoll.h>
#include <sys/timerfd.h>
+#endif
/* General queue */
