Fix multiple reload issue

core/vocabs/loader/loader.factor

@@ -160,13 +160,18 @@ SYMBOL: load-help?
 : load-failures. ( failures -- )
     [ load-error. nl ] each ;
 
+SYMBOL: blacklist
+
 : require-all ( vocabs -- failures )
     [
+        V{ } clone blacklist set
         [
             [
                 [ require ]
-                [ error-continuation get 3array , ]
-                recover
+                [
+                    over vocab-name blacklist get push
+                    error-continuation get 3array ,
+                ] recover
             ] each
         ] { } make
     ] with-compiler-errors ;
@@ -182,7 +187,7 @@ SYMBOL: load-help?
 : refresh-all ( -- ) "" refresh ;
 
 GENERIC: (load-vocab) ( name -- vocab )
-
+!
 M: vocab (load-vocab)
     dup vocab-root [
         dup vocab-source-loaded? [ dup load-source ] unless
@@ -195,8 +200,25 @@ M: string (load-vocab)
 M: vocab-link (load-vocab)
     vocab-name (load-vocab) ;
 
-[ [ dup vocab [ ] [ ] ?if (load-vocab) ] with-compiler-errors ]
-load-vocab-hook set-global
+TUPLE: blacklisted-vocab name ;
+!
+: blacklisted-vocab ( name -- * )
+    \ blacklisted-vocab construct-boa throw ;
+
+M: blacklisted-vocab error.
+    "This vocabulary depends on the " write
+    blacklisted-vocab-name write
+    " vocabulary which failed to load" print ;
+
+[
+    dup vocab-name blacklist get member? [
+        vocab-name blacklisted-vocab
+    ] [
+        [
+            dup vocab [ ] [ ] ?if (load-vocab)
+        ] with-compiler-errors
+    ] if
+] load-vocab-hook set-global
 
 : vocab-where ( vocab -- loc )
     vocab-source-path dup [ 1 2array ] when ;