Filter out incomplete foreign key definitions.

It's possible that in MySQL a foreign key constraint definition is
pointing to a non-existing table. In such a case, issue an error message
and refrain from trying to then reinstall the faulty foreign key
definition.

The lack of error handling at this point led to a frozen instance of
pgloader apparently, I think because it could not display the
interactive debugger at the point where the error occurs.

See #328, also #337 that might be fixed here.

src/sources/mysql/mysql-schema.lisp

@@ -306,7 +306,13 @@ FROM
                                                     (sq:split-sequence #\, fcols))
                                   :update-rule update-rule
                                   :delete-rule delete-rule)))
-           (add-fkey table fk))
+           (if (and name table ftable)
+               (add-fkey table fk)
+               (log-message :error
+                            "Incomplete Foreign Key definition: constraint ~s on table ~s referencing table ~s"
+                            name
+                            (when table (format-table-name table))
+                            (when ftable (format-table-name ftable)))))
      :finally
      (return schema)))
 

src/utils/monitor.lisp

@@ -198,7 +198,8 @@
                             (format nil "~{~}"
                                     (log-message-description event)
                                     (log-message-arguments event))
-                            (log-message-description event))))
+                            (log-message-description event)))
+                  (*print-circle* t))
               (cl-log:log-message (log-message-category event) "~a" mesg)))
 
            (new-label