Add debug flag of work dir deletion

_web_server/playground-server.scm

@@ -23,6 +23,7 @@
 
 (define INDEX-FILE "index.html")
 (define LOGGING #t)
+(define DELETE-WORK-DIR #t)
 
 (define (multistring . strings)
   (apply string-append
@@ -255,7 +256,8 @@
                                            (format "--\n~a\n" out)))))
                                  (string-append compile-log execution-log))))))))))
 
-            ;; (delete-recursive work-dir)
+            (when DELETE-WORK-DIR
+              (delete-recursive work-dir))
             log)))))
 
 ;;;