In OpenBSD initial thread local storage is allocated with calloc(),
which leads to locked mutexes and a stall. So no thread support
(and no tls) here.
MODIFY
libdislocator/libdislocator.so.c
libdislocator/libdislocator.so.c
@@ -88,6 +88,10 @@ static u8 alloc_verbose, /* Additional debug messages */
hard_fail, /* abort() when max_mem exceeded? */
no_calloc_over; /* abort() on calloc() overflows? */
+#ifdef __OpenBSD__
+#define __thread
+#warning no thread support available
+#endif
static __thread size_t total_mem; /* Currently allocated mem */
static __thread u32 call_depth; /* To avoid recursion via fprintf() */

In OpenBSD initial thread local storage is allocated with calloc(),
which leads to locked mutexes and a stall. So no thread support
(and no tls) here.