Report if cwd does not exist and raise exception in BaseIPythonApplication

Catch the exception in the starting scripts, report the exception
and exit gracefully. Do not directly exit in BaseIPythonApplication so
that external applications can also catch the exception instead of exiting.

IPython/core/application.py

@@ -147,18 +147,12 b' class BaseIPythonApplication(Application):'
     def __init__(self, **kwargs):
         super(BaseIPythonApplication, self).__init__(**kwargs)
         # ensure current working directory exists
-        level_up = False
-        while True:
-            try:
-                directory = os.getcwdu()
-            except OSError:
-                # search level up until directory exists
-                os.chdir("..")
-                level_up = True
-            else:
-                if level_up:
-                    self.log.warn("Current working directory doesn't exist.\nSetting to: %s"%(directory))
-                break
+        try:
+            directory = os.getcwdu()
+        except:
+            # raise exception
+            self.log.error("Current working directory doesn't exist.")
+            raise
 
         # ensure even default IPYTHONDIR exists
         if not os.path.exists(self.ipython_dir):

IPython/parallel/scripts/ipcluster

@@ -11,8 +11,15 b''
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
-
+import sys
+import traceback
 
 from IPython.parallel.apps.ipclusterapp import launch_new_instance
 
-launch_new_instance()
+try:
+    launch_new_instance()
+except:
+    exc_type, exc_value, exc_traceback = sys.exc_info()
+    traceback.print_exception(exc_type, exc_value, exc_traceback,
+                              file=sys.stderr)
+    sys.exit(1)

IPython/parallel/scripts/ipcontroller

@@ -11,8 +11,15 b''
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
-
+import sys
+import traceback
 
 from IPython.parallel.apps.ipcontrollerapp import launch_new_instance
 
-launch_new_instance()
+try:
+    launch_new_instance()
+except:
+    exc_type, exc_value, exc_traceback = sys.exc_info()
+    traceback.print_exception(exc_type, exc_value, exc_traceback,
+                              file=sys.stderr)
+    sys.exit(1)

IPython/parallel/scripts/ipengine

@@ -11,10 +11,15 b''
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
-
+import sys
+import traceback
 
 from IPython.parallel.apps.ipengineapp import launch_new_instance
 
-launch_new_instance()
-
-
+try:
+    launch_new_instance()
+except:
+    exc_type, exc_value, exc_traceback = sys.exc_info()
+    traceback.print_exception(exc_type, exc_value, exc_traceback,
+                              file=sys.stderr)
+    sys.exit(1)

IPython/parallel/scripts/iplogger

@@ -11,10 +11,15 b''
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
-
+import sys
+import traceback
 
 from IPython.parallel.apps.iploggerapp import launch_new_instance
 
-launch_new_instance()
-
-
+try:
+    launch_new_instance()
+except:
+    exc_type, exc_value, exc_traceback = sys.exc_info()
+    traceback.print_exception(exc_type, exc_value, exc_traceback,
+                              file=sys.stderr)
+    sys.exit(1)

IPython/scripts/ipython

@@ -1,7 +1,15 b''
 #!/usr/bin/env python
 """Terminal-based IPython entry point.
 """
+import sys
+import traceback
 
 from IPython.frontend.terminal.ipapp import launch_new_instance
 
-launch_new_instance()
+try:
+    launch_new_instance()
+except:
+    exc_type, exc_value, exc_traceback = sys.exc_info()
+    traceback.print_exception(exc_type, exc_value, exc_traceback,
+                              file=sys.stderr)
+    sys.exit(1)