For setting default external/internal encoding, loading should be done first

Loading needs to be outside of VM lock.

Author: luke-gruber

encoding.c

@@ -1614,6 +1614,10 @@ enc_set_default_encoding(struct default_encoding *def, VALUE encoding, const cha
         /* Already set */
         overridden = TRUE;
 
+    if (!NIL_P(encoding)) {
+        enc_check_encoding(encoding); // loads it if necessary. Needs to be done outside of VM lock.
+    }
+
     GLOBAL_ENC_TABLE_LOCKING(enc_table) {
         if (NIL_P(encoding)) {
             def->index = -1;