flask FlaskGroup does not work when nested in a click.group

The Fix

Upgrade to version 2.1.3 or later.

Based on closed pallets/flask issue #3263 · PR/commit linked

Production note: Most teams hit this during upgrades or environment changes. Roll out with a canary and smoke critical endpoints (health, OpenAPI/docs) before 100%.

Jump to Verify Open PR/Commit

@@ -25,6 +25,9 @@ Unreleased
     subclass sets this to ``False``, the view will not create a new
     instance on every request. :issue:`2520`.
+-   A ``flask.cli.FlaskGroup`` Click group can be nested as a
+    sub-command in a custom CLI. :issue:`3263`
+

repro.py

# flask app sub group
@my_big_cli_group.group(cls=FlaskGroup, create_app=create_app)
@click.pass_context
def my_flask_app(ctx):
    pass

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

fix.md

Option A — Upgrade to fixed release\nUpgrade to version 2.1.3 or later.\nWhen NOT to use: This fix should not be used if the application relies on the original FlaskGroup behavior.\n\nOption C — Workaround\nfor this to be allowed? I guess at the end `Flask` should be fully compatible with all `click` functionalities (group `nesting` being one of the main ones).\nWhen NOT to use: This fix should not be used if the application relies on the original FlaskGroup behavior.\n\n

Why This Fix Works in Production

Trigger: rv.update(info.load_app().cli.list_commands(ctx))
Mechanism: FlaskGroup's main function is not called when nested in another click group
Why the fix works: `FlaskGroup` can now be nested as a sub-command in a custom CLI, resolving the issue with `create_app` not being passed. (first fixed release: 2.1.3).

Production impact:

If left unfixed, the same config can fail only in production (env differences), causing startup failures or partial feature outages.

Why This Breaks in Prod

Shows up under Python 3.7 in real deployments (not just unit tests).
FlaskGroup's main function is not called when nested in another click group
Surfaces as: Traceback (most recent call last):

Proof / Evidence

GitHub issue: #3263
Fix PR: https://github.com/pallets/flask/pull/4642
First fixed release: 2.1.3
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.95
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.57

Discussion

High-signal excerpts from the issue thread (symptoms, repros, edge-cases).

Jump to Sources Open on GitHub

“There are some bootstrap code in FlaskGroup.main(), so I think it is not allowed to nest it in another group, because the function is never…”

@frostming · 2019-06-28 · source

“Ah, interesting. Could there be any workaround for this to be allowed? I guess at the end Flask should be fully compatible with all click…”

@gustapia06 · 2019-06-28 · source

“Passing create_app as a parameter doesn't work in this case, but you can still use FLASK_APP environment variable to do the trick. Note that some…”

@frostming · 2019-06-28 · source

“@u8sand Thanks a lot for your research! For anyone else wondering how to avoid this issue, this is the code I used (simplified a bit):”

@chatne · 2021-10-29 · source

Failure Signature (Search String)

rv.update(info.load_app().cli.list_commands(ctx))

Error Message

Stack trace

error.txt

Error Message
-------------
Traceback (most recent call last):
 File “/Users/the_user/Desktop/venv/lib/python3.7/site-packages/flask/cli.py”, line 540, in list_commands
   rv.update(info.load_app().cli.list_commands(ctx))
 File “/Users/the_user/Desktop/venv/lib/python3.7/site-packages/flask/cli.py”, line 393, in load_app
   ‘Could not locate a Flask application. You did not provide ’
flask.cli.NoAppException: Could not locate a Flask application. You did not provide the “FLASK_APP” environment variable, and a “wsgi.py” or “app.py” module was not found in the current directory.

Minimal Reproduction

repro.py

# flask app sub group
@my_big_cli_group.group(cls=FlaskGroup, create_app=create_app)
@click.pass_context
def my_flask_app(ctx):
    pass

Environment

Python: 3.7

What Broke

Running nested Flask commands results in a NoAppException error.

Why It Broke

FlaskGroup's main function is not called when nested in another click group

Fix Options (Details)

Option A — Upgrade to fixed release Safe default (recommended)

Upgrade to version 2.1.3 or later.

When NOT to use: This fix should not be used if the application relies on the original FlaskGroup behavior.

Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.

Option C — Workaround Temporary workaround

for this to be allowed? I guess at the end `Flask` should be fully compatible with all `click` functionalities (group `nesting` being one of the main ones).

When NOT to use: This fix should not be used if the application relies on the original FlaskGroup behavior.

Use only if you cannot change versions today. Treat this as a stopgap and remove once upgraded.

Fix reference: https://github.com/pallets/flask/pull/4642

First fixed release: 2.1.3

Last verified: 2026-02-09. Validate in your environment.

When NOT to Use This Fix

This fix should not be used if the application relies on the original FlaskGroup behavior.

Verify Fix

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

Did This Fix Work in Your Case?

Quick signal helps us prioritize which fixes to verify and improve.

Prevention

Capture the exact failing error string in logs and tests so you can reproduce via a minimal script.
Pin production dependencies and upgrade only with a reproducible test that hits the failing path.

Version Compatibility Table

Version	Status
2.1.3	Fixed

Related Issues

No related fixes found.

Cluster: flask:configuration-error All hubs All clusters

Related clusters: Data consistency Other Duplicate processing

Sources

We don’t republish the full GitHub discussion text. Use the links above for context.

flask FlaskGroup does not work when nested in a click.group (Fix)