PR: Show kernel initialization errors in the IPython console

spyder/app/mainwindow.py

@@ -301,6 +301,10 @@ def signal_handler(signum, frame=None):
             mac_style = mac_style.replace('$IMAGE_PATH', img_path)
             self.setStyleSheet(mac_style)
 
+        # Create our TEMPDIR
+        if not osp.isdir(programs.TEMPDIR):
+            os.mkdir(programs.TEMPDIR)
+
         # Shortcut management data
         self.shortcut_data = []
 

spyder/config/main.py

@@ -440,6 +440,7 @@
               # ---- In widgets/ipythonconsole/shell.py ----
               'ipython_console/new tab': "Ctrl+T",
               'ipython_console/reset namespace': "Ctrl+Alt+R",
+              'ipython_console/restart kernel': "Ctrl+.",
               # ---- In widgets/arraybuider.py ----
               'array_builder/enter array inline': "Ctrl+Alt+M",
               'array_builder/enter array table': "Ctrl+M",

spyder/plugins/ipythonconsole.py

@@ -15,6 +15,7 @@
 
 # Standard library imports
 import atexit
+import codecs
 import os
 import os.path as osp
 import uuid
@@ -728,20 +729,22 @@ def refresh_plugin(self):
         self.update_plugin_title.emit()
 
     def get_plugin_actions(self):
-        """Return a list of actions related to plugin"""
-        ctrl = "Cmd" if sys.platform == "darwin" else "Ctrl"
-        main_create_client_action = create_action(self,
-                                _("Open an &IPython console"),
-                                None, ima.icon('ipython_console'),
-                                triggered=self.create_new_client,
-                                tip=_("Use %s+T when the console is selected "
-                                      "to open a new one") % ctrl)
-        create_client_action = create_action(self,
-                                _("Open a new console"),
-                                QKeySequence("Ctrl+T"),
-                                ima.icon('ipython_console'),
-                                triggered=self.create_new_client,
-                                context=Qt.WidgetWithChildrenShortcut)
+        """Return a list of actions related to plugin."""
+        create_client_action = create_action(
+                                   self,
+                                   _("Open an &IPython console"),
+                                   icon=ima.icon('ipython_console'),
+                                   triggered=self.create_new_client,
+                                   context=Qt.WidgetWithChildrenShortcut)
+        self.register_shortcut(create_client_action, context="ipython_console",
+                               name="New tab")
+
+        restart_action = create_action(self, _("Restart kernel"),
+                                       icon=ima.icon('restart'),
+                                       triggered=self.restart_kernel,
+                                       context=Qt.WidgetWithChildrenShortcut)
+        self.register_shortcut(restart_action, context="ipython_console",
+                               name="Restart kernel")
 
         connect_to_kernel_action = create_action(self,
                _("Connect to an existing kernel"), None, None,
@@ -750,11 +753,13 @@ def get_plugin_actions(self):
 
         # Add the action to the 'Consoles' menu on the main window
         main_consoles_menu = self.main.consoles_menu_actions
-        main_consoles_menu.insert(0, main_create_client_action)
-        main_consoles_menu += [MENU_SEPARATOR, connect_to_kernel_action]
+        main_consoles_menu.insert(0, create_client_action)
+        main_consoles_menu += [MENU_SEPARATOR, restart_action,
+                               connect_to_kernel_action]
 
         # Plugin actions
-        self.menu_actions = [create_client_action, connect_to_kernel_action]
+        self.menu_actions = [restart_action, MENU_SEPARATOR,
+                             create_client_action, connect_to_kernel_action]
 
         return self.menu_actions
 
@@ -915,7 +920,9 @@ def create_client_for_kernel(self):
     def connect_client_to_kernel(self, client):
         """Connect a client to its kernel"""
         connection_file = client.connection_file
-        km, kc = self.create_kernel_manager_and_kernel_client(connection_file)
+        stderr_file = client.stderr_file
+        km, kc = self.create_kernel_manager_and_kernel_client(connection_file,
+                                                              stderr_file)
 
         kc.started_channels.connect(lambda c=client: self.process_started(c))
         kc.stopped_channels.connect(lambda c=client: self.process_finished(c))
@@ -1294,13 +1301,17 @@ def create_kernel_spec(self):
 
         return KernelSpec(resource_dir='', **kernel_dict)
 
-    def create_kernel_manager_and_kernel_client(self, connection_file):
-        """Create kernel manager and client"""
+    def create_kernel_manager_and_kernel_client(self, connection_file,
+                                                stderr_file):
+        """Create kernel manager and client."""
         # Kernel manager
         kernel_manager = QtKernelManager(connection_file=connection_file,
                                          config=None, autorestart=True)
         kernel_manager._kernel_spec = self.create_kernel_spec()
-        kernel_manager.start_kernel()
+
+        # Save stderr in a file to read it later in case of errors
+        stderr = codecs.open(stderr_file, 'w', encoding='utf-8')
+        kernel_manager.start_kernel(stderr=stderr)
 
         # Kernel client
         kernel_client = kernel_manager.client()
@@ -1311,6 +1322,12 @@ def create_kernel_manager_and_kernel_client(self, connection_file):
 
         return kernel_manager, kernel_client
 
+    def restart_kernel(self):
+        """Restart kernel of current client."""
+        client = self.get_current_client()
+        if client is not None:
+            client.restart_kernel()
+
     #------ Public API (for tabs) ---------------------------------------------
     def add_tab(self, widget, name):
         """Add tab"""

spyder/utils/programs.py

@@ -396,9 +396,6 @@ def is_module_installed(module_name, version=None, installed_version=None,
     in a determined interpreter
     """
     if interpreter:
-        if not osp.isdir(TEMPDIR):
-            os.mkdir(TEMPDIR)
-
         if osp.isfile(interpreter) and ('python' in interpreter):
             checkver = inspect.getsource(check_version)
             get_modver = inspect.getsource(get_module_version)

spyder/widgets/ipythonconsole/client.py

@@ -13,6 +13,7 @@
 # Standard library imports
 from __future__ import absolute_import  # Fix for Issue 1356
 
+import codecs
 import os
 import os.path as osp
 from string import Template
@@ -30,6 +31,8 @@
                                 get_module_source_path)
 from spyder.config.gui import get_font, get_shortcut
 from spyder.utils import icon_manager as ima
+from spyder.utils import sourcecode
+from spyder.utils.programs import TEMPDIR
 from spyder.utils.qthelpers import (add_actions, create_action,
                                     create_toolbutton)
 from spyder.widgets.browser import WebView
@@ -103,16 +106,15 @@ def __init__(self, plugin, name, history_filename, config_options,
 
         # --- Widgets
         self.shellwidget = ShellWidget(config=config_options,
+                                       ipyclient=self,
                                        additional_options=additional_options,
                                        interpreter_versions=interpreter_versions,
                                        external_kernel=external_kernel,
                                        local_kernel=True)
-        self.shellwidget.hide()
         self.infowidget = WebView(self)
         self.set_infowidget_font()
         self.loading_page = self._create_loading_page()
-        self.infowidget.setHtml(self.loading_page,
-                                QUrl.fromLocalFile(CSS_PATH))
+        self._show_loading_page()
 
         # --- Layout
         vlayout = QVBoxLayout()
@@ -133,16 +135,24 @@ def __init__(self, plugin, name, history_filename, config_options,
         # As soon as some content is printed in the console, stop
         # our loading animation
         document = self.get_control().document()
-        document.contentsChange.connect(self._stop_loading_animation)
+        document.contentsChange.connect(self._hide_loading_page)
 
     #------ Public API --------------------------------------------------------
+    @property
+    def stderr_file(self):
+        """Filename to save kernel stderr output."""
+        json_file = osp.basename(self.connection_file)
+        stderr_file = json_file.split('json')[0] + 'stderr'
+        stderr_file = osp.join(TEMPDIR, stderr_file)
+        return stderr_file
+
     def configure_shellwidget(self, give_focus=True):
         """Configure shellwidget after kernel is started"""
         if give_focus:
             self.get_control().setFocus()
 
-        # Connect shellwidget to the client
-        self.shellwidget.set_ipyclient(self)
+        # Set exit callback
+        self.shellwidget.set_exit_callback()
 
         # To save history
         self.shellwidget.executing.connect(self.add_to_history)
@@ -163,6 +173,10 @@ def configure_shellwidget(self, give_focus=True):
         # To disable the stop button after execution stopped
         self.shellwidget.executed.connect(self.disable_stop_button)
 
+        # To show kernel restarted/died messages
+        self.shellwidget.sig_kernel_restarted.connect(
+            self.kernel_restarted_message)
+
     def enable_stop_button(self):
         self.stop_button.setEnabled(True)
 
@@ -180,7 +194,12 @@ def stop_button_click_handler(self):
             self.shellwidget.write_to_stdin('exit')
 
     def show_kernel_error(self, error):
-        """Show kernel initialization errors in infowidget"""
+        """Show kernel initialization errors in infowidget."""
+        # Replace end of line chars with <br>
+        eol = sourcecode.get_eol_chars(error)
+        if eol:
+            error = error.replace(eol, '<br>')
+
         # Don't break lines in hyphens
         # From http://stackoverflow.com/q/7691569/438386
         error = error.replace('-', '&#8209')
@@ -217,27 +236,18 @@ def get_kernel(self):
 
     def get_options_menu(self):
         """Return options menu"""
-        restart_action = create_action(self, _("Restart kernel"),
-                                       shortcut=QKeySequence("Ctrl+."),
-                                       icon=ima.icon('restart'),
-                                       triggered=self.restart_kernel,
-                                       context=Qt.WidgetWithChildrenShortcut)
-
-        # Main menu
-        if self.menu_actions is not None:
-            actions = [restart_action, None] + self.menu_actions
-        else:
-            actions = [restart_action]
-        return actions
+        return self.menu_actions
 
     def get_toolbar_buttons(self):
-        """Return toolbar buttons list"""
+        """Return toolbar buttons list."""
         buttons = []
         # Code to add the stop button
         if self.stop_button is None:
-            self.stop_button = create_toolbutton(self, text=_("Stop"),
-                                             icon=self.stop_icon,
-                                             tip=_("Stop the current command"))
+            self.stop_button = create_toolbutton(
+                                   self,
+                                   text=_("Stop"),
+                                   icon=self.stop_icon,
+                                   tip=_("Stop the current command"))
             self.disable_stop_button()
             # set click event handler
             self.stop_button.clicked.connect(self.stop_button_click_handler)
@@ -320,6 +330,9 @@ def restart_kernel(self):
         if result == QMessageBox.Yes:
             sw = self.shellwidget
             if sw.kernel_manager:
+                if self.infowidget.isVisible():
+                    self.infowidget.hide()
+                    sw.show()
                 try:
                     sw.kernel_manager.restart_kernel()
                 except RuntimeError as e:
@@ -328,15 +341,28 @@ def restart_kernel(self):
                         before_prompt=True
                     )
                 else:
+                    sw.reset(clear=True)
                     sw._append_html(_("<br>Restarting kernel...\n<hr><br>"),
-                        before_prompt=True,
+                        before_prompt=False,
                     )
             else:
                 sw._append_plain_text(
                     _('Cannot restart a kernel not started by Spyder\n'),
                     before_prompt=True
                 )
 
+    @Slot(str)
+    def kernel_restarted_message(self, msg):
+        """Show kernel restarted/died messages."""
+        stderr = codecs.open(self.stderr_file, 'r', encoding='utf-8').read()
+
+        if stderr:
+            self.show_kernel_error('<tt>%s</tt>' % stderr)
+        else:
+            self.shellwidget._append_html("<br>%s<hr><br>" % msg,
+                                          before_prompt=False)
+
+
     @Slot()
     def inspect_object(self):
         """Show how to inspect an object with our Help plugin"""
@@ -390,11 +416,18 @@ def _create_loading_page(self):
                                            message=message)
         return page
 
-    def _stop_loading_animation(self):
-        """Stop animation shown while the kernel is starting"""
+    def _show_loading_page(self):
+        """Show animation while the kernel is loading."""
+        self.shellwidget.hide()
+        self.infowidget.show()
+        self.infowidget.setHtml(self.loading_page,
+                                QUrl.fromLocalFile(CSS_PATH))
+
+    def _hide_loading_page(self):
+        """Hide animation shown while the kernel is loading."""
         self.infowidget.hide()
         self.shellwidget.show()
         self.infowidget.setHtml(BLANK)
 
         document = self.get_control().document()
-        document.contentsChange.disconnect(self._stop_loading_animation)
+        document.contentsChange.disconnect(self._hide_loading_page)

spyder/widgets/ipythonconsole/shell.py

@@ -45,33 +45,32 @@ class ShellWidget(NamepaceBrowserWidget, HelpWidget, DebuggingWidget):
     focus_changed = Signal()
     new_client = Signal()
     sig_got_reply = Signal()
+    sig_kernel_restarted = Signal(str)
 
-    def __init__(self, additional_options, interpreter_versions,
+    def __init__(self, ipyclient, additional_options, interpreter_versions,
                  external_kernel, *args, **kw):
         # To override the Qt widget used by RichJupyterWidget
         self.custom_control = ControlWidget
         self.custom_page_control = PageControlWidget
         super(ShellWidget, self).__init__(*args, **kw)
+
+        self.ipyclient = ipyclient
         self.additional_options = additional_options
         self.interpreter_versions = interpreter_versions
+        self.external_kernel = external_kernel
 
         self.set_background_color()
 
-        # Additional variables
-        self.ipyclient = None
-        self.external_kernel = external_kernel
-
         # Keyboard shortcuts
         self.shortcuts = self.create_shortcuts()
 
         # To save kernel replies in silent execution
         self._kernel_reply = None
 
     #---- Public API ----------------------------------------------------------
-    def set_ipyclient(self, ipyclient):
-        """Bind this shell widget to an IPython client one"""
-        self.ipyclient = ipyclient
-        self.exit_requested.connect(ipyclient.exit_callback)
+    def set_exit_callback(self):
+        """Set exit callback for this shell."""
+        self.exit_requested.connect(self.ipyclient.exit_callback)
 
     def is_running(self):
         if self.kernel_client is not None and \
@@ -165,6 +164,9 @@ def create_shortcuts(self):
                                   parent=self)
         clear_console = config_shortcut(self.clear_console, context='Console',
                                         name='Clear shell', parent=self)
+        restart_kernel = config_shortcut(self.ipyclient.restart_kernel,
+                                         context='ipython_console',
+                                         name='Restart kernel', parent=self)
         new_tab = config_shortcut(lambda: self.new_client.emit(),
                                   context='ipython_console', name='new tab', parent=self)
         reset_namespace = config_shortcut(lambda: self.reset_namespace(),
@@ -177,8 +179,8 @@ def create_shortcuts(self):
                                       context='array_builder',
                                       name='enter array table', parent=self)
 
-        return [inspect, clear_console, new_tab, reset_namespace,
-                array_inline, array_table]
+        return [inspect, clear_console, restart_kernel, new_tab,
+                reset_namespace, array_inline, array_table]
 
     # --- To communicate with the kernel
     def silent_execute(self, code):
@@ -274,6 +276,10 @@ def _banner_default(self):
         else:
             return self.short_banner()
 
+    def _kernel_restarted_message(self, died=True):
+        msg = _("Kernel died, restarting") if died else _("Kernel restarting")
+        self.sig_kernel_restarted.emit(msg)
+
     #---- Qt methods ----------------------------------------------------------
     def focusInEvent(self, event):
         """Reimplement Qt method to send focus change notification"""