switch order of failed-to-start errors in test_embed_kernel

also increase timeout for kernel start to 10 seconds

IPython/zmq/tests/test_embed_kernel.py

@@ -1,188 +1,190 b''
 """test IPython.embed_kernel()"""
 
 #-------------------------------------------------------------------------------
 #  Copyright (C) 2012  The IPython Development Team
 #
 #  Distributed under the terms of the BSD License.  The full license is in
 #  the file COPYING, distributed as part of this software.
 #-------------------------------------------------------------------------------
 
 #-------------------------------------------------------------------------------
 # Imports
 #-------------------------------------------------------------------------------
 
 import os
 import shutil
 import sys
 import tempfile
 import time
 
 from contextlib import contextmanager
 from subprocess import Popen, PIPE
 
 import nose.tools as nt
 
 from IPython.zmq.blockingkernelmanager import BlockingKernelManager
-from IPython.utils import path
+from IPython.utils import path, py3compat
 
 
 #-------------------------------------------------------------------------------
 # Tests
 #-------------------------------------------------------------------------------
 
 def setup():
     """setup temporary IPYTHONDIR for tests"""
     global IPYTHONDIR
     global env
     global save_get_ipython_dir
     
     IPYTHONDIR = tempfile.mkdtemp()
     env = dict(IPYTHONDIR=IPYTHONDIR)
     save_get_ipython_dir = path.get_ipython_dir
     path.get_ipython_dir = lambda : IPYTHONDIR
 
 
 def teardown():
     path.get_ipython_dir = save_get_ipython_dir
     
     try:
         shutil.rmtree(IPYTHONDIR)
     except (OSError, IOError):
         # no such file
         pass
 
 
 @contextmanager
 def setup_kernel(cmd):
     """start an embedded kernel in a subprocess, and wait for it to be ready
     
     Returns
     -------
     kernel_manager: connected KernelManager instance
     """
     kernel = Popen([sys.executable, '-c', cmd], stdout=PIPE, stderr=PIPE, env=env)
     connection_file = os.path.join(IPYTHONDIR,
                                     'profile_default',
                                     'security',
                                     'kernel-%i.json' % kernel.pid
     )
     # wait for connection file to exist, timeout after 5s
     tic = time.time()
-    while not os.path.exists(connection_file) and kernel.poll() is None and time.time() < tic + 5:
+    while not os.path.exists(connection_file) and kernel.poll() is None and time.time() < tic + 10:
         time.sleep(0.1)
     
+    if kernel.poll() is not None:
+        o,e = kernel.communicate()
+        e = py3compat.cast_unicode(e)
+        raise IOError("Kernel failed to start:\n%s" % e)
+    
     if not os.path.exists(connection_file):
         if kernel.poll() is None:
             kernel.terminate()
         raise IOError("Connection file %r never arrived" % connection_file)
     
-    if kernel.poll() is not None:
-        raise IOError("Kernel failed to start")
-    
     km = BlockingKernelManager(connection_file=connection_file)
     km.load_connection_file()
     km.start_channels()
     
     try:
         yield km
     finally:
         km.stop_channels()
 
 def test_embed_kernel_basic():
     """IPython.embed_kernel() is basically functional"""
     cmd = '\n'.join([
         'from IPython import embed_kernel',
         'def go():',
         '    a=5',
         '    b="hi there"',
         '    embed_kernel()',
         'go()',
         '',
     ])
     
     with setup_kernel(cmd) as km:
         shell = km.shell_channel
     
         # oinfo a (int)
         msg_id = shell.object_info('a')
         msg = shell.get_msg(block=True, timeout=2)
         content = msg['content']
         nt.assert_true(content['found'])
     
         msg_id = shell.execute("c=a*2")
         msg = shell.get_msg(block=True, timeout=2)
         content = msg['content']
         nt.assert_equals(content['status'], u'ok')
 
         # oinfo c (should be 10)
         msg_id = shell.object_info('c')
         msg = shell.get_msg(block=True, timeout=2)
         content = msg['content']
         nt.assert_true(content['found'])
         nt.assert_equals(content['string_form'], u'10')
 
 def test_embed_kernel_namespace():
     """IPython.embed_kernel() inherits calling namespace"""
     cmd = '\n'.join([
         'from IPython import embed_kernel',
         'def go():',
         '    a=5',
         '    b="hi there"',
         '    embed_kernel()',
         'go()',
         '',
     ])
     
     with setup_kernel(cmd) as km:
         shell = km.shell_channel
     
         # oinfo a (int)
         msg_id = shell.object_info('a')
         msg = shell.get_msg(block=True, timeout=2)
         content = msg['content']
         nt.assert_true(content['found'])
         nt.assert_equals(content['string_form'], u'5')
 
         # oinfo b (str)
         msg_id = shell.object_info('b')
         msg = shell.get_msg(block=True, timeout=2)
         content = msg['content']
         nt.assert_true(content['found'])
         nt.assert_equals(content['string_form'], u'hi there')
 
         # oinfo c (undefined)
         msg_id = shell.object_info('c')
         msg = shell.get_msg(block=True, timeout=2)
         content = msg['content']
         nt.assert_false(content['found'])
 
 def test_embed_kernel_reentrant():
     """IPython.embed_kernel() can be called multiple times"""
     cmd = '\n'.join([
         'from IPython import embed_kernel',
         'count = 0',
         'def go():',
         '    global count',
         '    embed_kernel()',
         '    count = count + 1',
         '',
         'while True:'
         '    go()',
         '',
     ])
     
     with setup_kernel(cmd) as km:
         shell = km.shell_channel
         for i in range(5):
             msg_id = shell.object_info('count')
             msg = shell.get_msg(block=True, timeout=2)
             content = msg['content']
             nt.assert_true(content['found'])
             nt.assert_equals(content['string_form'], unicode(i))
             
             # exit from embed_kernel
             shell.execute("get_ipython().exit_now = True")
             msg = shell.get_msg(block=True, timeout=2)
             time.sleep(0.2)