From 5b7fd9ad889e54d4d694d310b559c921d7df75cf Mon Sep 17 00:00:00 2001
From: Sven-Hendrik Haase <svenstaro@gmail.com>
Date: Thu, 16 Mar 2017 14:37:58 +0100
Subject: [PATCH 1/3] Print a stacktrace on CLI error (closes #2208)

---
 flask/cli.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/flask/cli.py b/flask/cli.py
index bde5a13b..8f8fac03 100644
--- a/flask/cli.py
+++ b/flask/cli.py
@@ -11,6 +11,7 @@
 
 import os
 import sys
+import traceback
 from threading import Lock, Thread
 from functools import update_wrapper
 
@@ -368,6 +369,9 @@ 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.
+            # However, we will not do so silently because that would confuse
+            # users.
+            traceback.print_exc()
             pass
         return sorted(rv)
 

From ad42d88fb2cda12a21c4fb6f002f425f233d1fe3 Mon Sep 17 00:00:00 2001
From: Sven-Hendrik Haase <svenstaro@gmail.com>
Date: Thu, 16 Mar 2017 14:42:09 +0100
Subject: [PATCH 2/3] Remove useless pass

---
 flask/cli.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/flask/cli.py b/flask/cli.py
index 8f8fac03..8db7e07e 100644
--- a/flask/cli.py
+++ b/flask/cli.py
@@ -372,7 +372,6 @@ class FlaskGroup(AppGroup):
             # However, we will not do so silently because that would confuse
             # users.
             traceback.print_exc()
-            pass
         return sorted(rv)
 
     def main(self, *args, **kwargs):

From ed17bc171046a15f03c890687db8eb9652513bd9 Mon Sep 17 00:00:00 2001
From: Sven-Hendrik Haase <svenstaro@gmail.com>
Date: Thu, 16 Mar 2017 20:56:12 +0100
Subject: [PATCH 3/3] Add test to showcase that printing a traceback works

---
 tests/test_cli.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/tests/test_cli.py b/tests/test_cli.py
index 313a34d2..82c69f93 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -191,3 +191,20 @@ def test_flaskgroup():
     result = runner.invoke(cli, ['test'])
     assert result.exit_code == 0
     assert result.output == 'flaskgroup\n'
+
+
+def test_print_exceptions():
+    """Print the stacktrace if the CLI."""
+    def create_app(info):
+        raise Exception("oh no")
+        return Flask("flaskgroup")
+
+    @click.group(cls=FlaskGroup, create_app=create_app)
+    def cli(**params):
+        pass
+
+    runner = CliRunner()
+    result = runner.invoke(cli, ['--help'])
+    assert result.exit_code == 0
+    assert 'Exception: oh no' in result.output
+    assert 'Traceback' in result.output