This fixes https://github.com/akheron/jansson/issues/434

src/dump.c

@@ -61,8 +61,8 @@ static int dump_to_file(const char *buffer, size_t size, void *data)
 
 static int dump_to_fd(const char *buffer, size_t size, void *data)
 {
-    int *dest = (int *)data;
 #ifdef HAVE_UNISTD_H
+    int *dest = (int *)data;
     if(write(*dest, buffer, size) == (ssize_t)size)
         return 0;
 #endif

src/load.c

@@ -1034,8 +1034,8 @@ json_t *json_loadf(FILE *input, size_t flags, json_error_t *error)
 
 static int fd_get_func(int *fd)
 {
-    uint8_t c;
 #ifdef HAVE_UNISTD_H
+    uint8_t c;
     if (read(*fd, &c, 1) == 1)
         return c;
 #endif