Catch web browser launching failure

config.ru

@@ -43,12 +43,20 @@ if "#{$PROGRAM_NAME}".include?("tabula.jar")
   if have_desktop
     puts "\n======================================================"
     puts "Launching web browser to #{url}\n\n"
-    puts "If it does not open in 10 seconds, you may manually open"
-    puts "a web browser to the above URL."
+
+    begin
+      desktop.browse(uri)
+    rescue
+      puts "Unable to launch your web browser, you will have to"
+      puts "manually open it to the above URL."
+    else
+      puts "If it does not open in 10 seconds, you may manually open"
+      puts "a web browser to the above URL."
+    end
+
     puts "When you're done using the Tabula interface, you may"
     puts "return to this window and press \"Control-C\" to close it."
     puts "======================================================\n\n"
-    desktop.browse(uri)
   else
     puts "\n======================================================"
     puts "Server now listening at: #{url}\n\n"