From 31d0eac8a4e7b9ba4dcc06cb093df01a2241ab0c 2011-12-06 01:40:59
From: Paul Ivanov <pivanov314@gmail.com>
Date: 2011-12-06 01:40:59
Subject: [PATCH] report inability to signal --existing kernels

---

diff --git a/IPython/frontend/zmqterminal/app.py b/IPython/frontend/zmqterminal/app.py
index 6a5faf9..df213cc 100644
--- a/IPython/frontend/zmqterminal/app.py
+++ b/IPython/frontend/zmqterminal/app.py
@@ -102,7 +102,11 @@ class ZMQTerminalIPythonApp(TerminalIPythonApp, IPythonMixinConsoleApp):
 
     def handle_sigint(self, *args):
         self.shell.write('KeyboardInterrupt\n')
-        self.kernel_manager.interrupt_kernel()
+        if self.kernel_manager.has_kernel:
+            self.kernel_manager.interrupt_kernel()
+        else:
+            print 'Kernel process is either remote or unspecified.',
+            print 'Cannot interrupt.'
 
     def init_code(self):
         # no-op in the frontend, code gets run in the backend