Merge branch 'master' into routes-command

flask/cli.py

@@ -11,6 +11,7 @@
 
 import os
 import sys
+import traceback
 from threading import Lock, Thread
 from functools import update_wrapper
 
@@ -86,7 +87,21 @@ def locate_app(app_id):
         module = app_id
         app_obj = None
 
-    __import__(module)
+    try:
+        __import__(module)
+    except ImportError:
+        # Reraise the ImportError if it occurred within the imported module.
+        # Determine this by checking whether the trace has a depth > 1.
+        if sys.exc_info()[-1].tb_next:
+            stack_trace = traceback.format_exc()
+            raise NoAppException('There was an error trying to import'
+                    ' the app (%s):\n%s' % (module, stack_trace))
+        else:
+            raise NoAppException('The file/path provided (%s) does not appear'
+                                 ' to exist.  Please verify the path is '
+                                 'correct.  If app is not on PYTHONPATH, '
+                                 'ensure the extension is .py' % module)
+
     mod = sys.modules[module]
     if app_obj is None:
         app = find_best_app(mod)
@@ -125,9 +140,9 @@ version_option = click.Option(['--version'],
                               is_flag=True, is_eager=True)
 
 class DispatchingApp(object):
-    """Special application that dispatches to a flask application which
+    """Special application that dispatches to a Flask application which
     is imported by name in a background thread.  If an error happens
-    it is is recorded and shows as part of the WSGI handling which in case
+    it is recorded and shown as part of the WSGI handling which in case
     of the Werkzeug debugger means that it shows up in the browser.
     """
 
@@ -286,7 +301,7 @@ class FlaskGroup(AppGroup):
 
     :param add_default_commands: if this is True then the default run and
                                  shell commands wil be added.
-    :param add_version_option: adds the :option:`--version` option.
+    :param add_version_option: adds the ``--version`` option.
     :param create_app: an optional callback that is passed the script info
                        and returns the loaded app.
     """
@@ -357,7 +372,9 @@ class FlaskGroup(AppGroup):
             # want the help page to break if the app does not exist.
             # If someone attempts to use the command we try to create
             # the app again and this will give us the error.
-            pass
+            # However, we will not do so silently because that would confuse
+            # users.
+            traceback.print_exc()
         return sorted(rv)
 
     def main(self, *args, **kwargs):
@@ -401,6 +418,13 @@ def run_command(info, host, port, reload, debugger, eager_loading,
     """
     from werkzeug.serving import run_simple
 
+    # Set a global flag that indicates that we were invoked from the
+    # command line interface provided server command.  This is detected
+    # by Flask.run to make the call into a no-op.  This is necessary to
+    # avoid ugly errors when the script that is loaded here also attempts
+    # to start a server.
+    os.environ['FLASK_RUN_FROM_CLI_SERVER'] = '1'
+
     debug = get_debug_flag()
     if reload is None:
         reload = bool(debug)
@@ -411,7 +435,7 @@ def run_command(info, host, port, reload, debugger, eager_loading,
 
     app = DispatchingApp(info.load_app, use_eager_loading=eager_loading)
 
-    # Extra startup messages.  This depends a but on Werkzeug internals to
+    # Extra startup messages.  This depends a bit on Werkzeug internals to
     # not double execute when the reloader kicks in.
     if os.environ.get('WERKZEUG_RUN_MAIN') != 'true':
         # If we have an import path we can print it out now which can help
@@ -424,8 +448,7 @@ def run_command(info, host, port, reload, debugger, eager_loading,
             print(' * Forcing debug mode %s' % (debug and 'on' or 'off'))
 
     run_simple(host, port, app, use_reloader=reload,
-               use_debugger=debugger, threaded=with_threads,
-               passthrough_errors=True)
+               use_debugger=debugger, threaded=with_threads)
 
 
 @click.command('shell', short_help='Runs a shell in the app context.')
@@ -495,7 +518,7 @@ def routes_command(order_by):
 cli = FlaskGroup(help="""\
 This shell command acts as general utility script for Flask applications.
 
-It loads the application configured (either through the FLASK_APP environment
+It loads the application configured (through the FLASK_APP environment
 variable) and then provides commands either provided by the application or
 Flask itself.