fix error message for unsupported patterns

pkgs/redex-pkgs/redex-lib/redex/private/generate-term.rkt

@@ -155,7 +155,8 @@
                                             [else (redex-error 'redex-check "~s does not match ~s" generated 'res-term-stx)]))])
                     syncheck-exp
                     (let ([default-attempt-size (λ (s) (add1 (default-attempt-size s)))])
-                      (parameterize ([attempt->size #,size-stx])
+                      (parameterize ([attempt->size #,size-stx]
+                                     [unsupported-pat-err-name 'redex-check])
                         (check-one
                          (λ (size _1 _2)
                            (values

pkgs/redex-pkgs/redex-test/redex/tests/rg-test.rkt

@@ -1391,6 +1391,22 @@
                   #:keep-going? #t)))
   (test tries 10))
 
+(let ()
+  (define-language L)
+  
+  (define-judgment-form L 
+    #:mode (wf I)
+    [--------------
+     (wf (any ...))])
+
+  (test (regexp-match?
+         #rx"^redex-check: generation failed at unsupported pattern"
+         (with-handlers ([exn:fail? exn-message])
+           (redex-check L #:satisfying (wf any) #t)
+           "no exn raised"))
+        #t))
+
+
 ;; redex-test-seed
 (let ([seed 0])
   (define-language L)