🐛 [BUG] Startup failure on app created with warehouse resource

[maucaro]

Created an app with with a warehouse resource (apx init)

Tried to run the app (apx dev start)

Output:
🛫 Preflight check started...
✓ verified project layout (0ms)
✓ uv sync (17ms)
✓ version file (619ms)
✓ node_modules (cached)
✅ Ready for takeoff! (1s 385ms)

🚀 Starting dev server...
⏳ Waiting for dev server to become healthy...

2026-02-24 08:21:02.826 | db | out | Resolving dependencies
2026-02-24 08:21:03.241 | db | out | Resolved, downloaded and extracted [2]
2026-02-24 08:21:03.277 | db | out | Saved lockfile
2026-02-24 08:21:03.533 | db | out | Initializing PGLite with database: memory://
2026-02-24 08:21:03.534 | db | out | Debug level: 0
2026-02-24 08:21:04.105 | db | out | PGlite database initialized
2026-02-24 08:21:04.108 | db | out | PGLiteSocketServer listening on {"port":4908,"host":"0.0.0.0"}
2026-02-24 08:21:04.132 | db | out | Client connected from 127.0.0.1:58569
2026-02-24 08:21:04.696 | app | out | INFO / uvicorn.error / Will watch for changes in these directories: ['/Users/mauricio.caro/Code/apx-apps/hw1']
2026-02-24 08:21:04.696 | app | out | INFO / uvicorn.error / Uvicorn running on http://0.0.0.0:8050 (Press CTRL+C to quit)
2026-02-24 08:21:04.697 | app | out | INFO / uvicorn.error / Started reloader process [44829] using StatReload
2026-02-24 08:21:04.536 | ui | out | Starting frontend dev server...
2026-02-24 08:21:04.536 | ui | out | Config: port=5177, devServerPort=9001, devServerHost=0.0.0.0, frontendHost=127.0.0.1
2026-02-24 08:21:04.539 | ui | out | Creating vite server...
2026-02-24 08:21:04.640 | ui | out | Starting to listen...
2026-02-24 08:21:04.649 | ui | out | [READY] Frontend server listening on port 5177
2026-02-24 08:21:04.743 | ui | out | Redirecting to: http://127.0.0.1:9001/
2026-02-24 08:21:05.395 | app | out | INFO / uvicorn.error / Started server process [44842]
2026-02-24 08:21:05.395 | app | out | INFO / uvicorn.error / Waiting for application startup.
2026-02-24 08:21:05.396 | app | out | INFO / fast-wolf / Starting app with configuration:
2026-02-24 08:21:05.396 | app | out | app_name='fast-wolf'
2026-02-24 08:21:05.396 | app | out | INFO / databricks.sdk / loading DEFAULT profile from ~/.databrickscfg: host, auth_type
2026-02-24 08:21:05.414 | app | out | INFO / databricks.sdk / Using Databricks CLI authentication
2026-02-24 08:21:05.417 | app | err | ERROR / uvicorn.error / Traceback (most recent call last):
2026-02-24 08:21:05.417 | app | out | File "/Users/mauricio.caro/Code/apx-apps/hw1/.venv/lib/python3.11/site-packages/starlette/routing.py", line 694, in lifespan
2026-02-24 08:21:05.418 | app | out | async with self.lifespan_context(app) as maybe_state:
2026-02-24 08:21:05.418 | app | out | File "/Users/mauricio.caro/.pyenv/versions/3.11.10/lib/python3.11/contextlib.py", line 210, in aenter
2026-02-24 08:21:05.419 | app | out | return await anext(self.gen)
2026-02-24 08:21:05.419 | app | out | ^^^^^^^^^^^^^^^^^^^^^
2026-02-24 08:21:05.419 | app | out | File "/Users/mauricio.caro/Code/apx-apps/hw1/.venv/lib/python3.11/site-packages/fastapi/routing.py", line 201, in merged_lifespan
2026-02-24 08:21:05.419 | app | out | async with original_context(app) as maybe_original_state:
2026-02-24 08:21:05.420 | app | out | File "/Users/mauricio.caro/.pyenv/versions/3.11.10/lib/python3.11/contextlib.py", line 210, in aenter
2026-02-24 08:21:05.420 | app | out | return await anext(self.gen)
2026-02-24 08:21:05.420 | app | out | ^^^^^^^^^^^^^^^^^^^^^
2026-02-24 08:21:05.420 | app | out | File "/Users/mauricio.caro/Code/apx-apps/hw1/src/fast_wolf/backend/core/_factory.py", line 62, in _composed_lifespan
2026-02-24 08:21:05.421 | app | out | async with _chain_dep_lifespans(all_deps, app):
2026-02-24 08:21:05.421 | app | out | File "/Users/mauricio.caro/.pyenv/versions/3.11.10/lib/python3.11/contextlib.py", line 210, in aenter
2026-02-24 08:21:05.421 | app | out | return await anext(self.gen)
2026-02-24 08:21:05.421 | app | out | ^^^^^^^^^^^^^^^^^^^^^
2026-02-24 08:21:05.421 | app | out | File "/Users/mauricio.caro/Code/apx-apps/hw1/src/fast_wolf/backend/core/_factory.py", line 29, in _chain_dep_lifespans
2026-02-24 08:21:05.422 | app | out | async with _chain_dep_lifespans(tail, app):
2026-02-24 08:21:05.422 | app | out | File "/Users/mauricio.caro/.pyenv/versions/3.11.10/lib/python3.11/contextlib.py", line 210, in aenter
2026-02-24 08:21:05.422 | app | out | return await anext(self.gen)
2026-02-24 08:21:05.423 | app | out | ^^^^^^^^^^^^^^^^^^^^^
2026-02-24 08:21:05.423 | app | out | File "/Users/mauricio.caro/Code/apx-apps/hw1/src/fast_wolf/backend/core/_factory.py", line 29, in _chain_dep_lifespans
2026-02-24 08:21:05.423 | app | out | async with _chain_dep_lifespans(tail, app):
2026-02-24 08:21:05.423 | app | out | File "/Users/mauricio.caro/.pyenv/versions/3.11.10/lib/python3.11/contextlib.py", line 210, in aenter
2026-02-24 08:21:05.423 | app | out | return await anext(self.gen)
2026-02-24 08:21:05.424 | app | out | ^^^^^^^^^^^^^^^^^^^^^
2026-02-24 08:21:05.424 | app | out | File "/Users/mauricio.caro/Code/apx-apps/hw1/src/fast_wolf/backend/core/_factory.py", line 28, in _chain_dep_lifespans
2026-02-24 08:21:05.424 | app | out | async with head.lifespan(app):
2026-02-24 08:21:05.424 | app | out | File "/Users/mauricio.caro/.pyenv/versions/3.11.10/lib/python3.11/contextlib.py", line 210, in aenter
2026-02-24 08:21:05.424 | app | out | return await anext(self.gen)
2026-02-24 08:21:05.425 | app | out | ^^^^^^^^^^^^^^^^^^^^^
2026-02-24 08:21:05.425 | app | out | File "/Users/mauricio.caro/Code/apx-apps/hw1/src/fast_wolf/backend/core/sql.py", line 46, in lifespan
2026-02-24 08:21:05.425 | app | out | app.state.sql_config = SqlConfig() # ty: ignore[missing-argument]
2026-02-24 08:21:05.425 | app | out | ^^^^^^^^^^^
2026-02-24 08:21:05.425 | app | out | File "/Users/mauricio.caro/Code/apx-apps/hw1/.venv/lib/python3.11/site-packages/pydantic_settings/main.py", line 242, in init
2026-02-24 08:21:05.426 | app | out | super().init(**pydantic_self.class._settings_build_values(sources, init_kwargs))
2026-02-24 08:21:05.426 | app | out | File "/Users/mauricio.caro/Code/apx-apps/hw1/.venv/lib/python3.11/site-packages/pydantic/main.py", line 250, in init
2026-02-24 08:21:05.426 | app | out | validated_self = self.pydantic_validator.validate_python(data, self_instance=self)
2026-02-24 08:21:05.427 | app | out | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2026-02-24 08:21:05.427 | app | out | pydantic_core._pydantic_core.ValidationError: 1 validation error for SqlConfig
2026-02-24 08:21:05.427 | app | out | warehouse_id
2026-02-24 08:21:05.427 | app | out | Field required [type=missing, input_value={}, input_type=dict]
2026-02-24 08:21:05.427 | app | out | For further information visit https://errors.pydantic.dev/2.12/v/missing
2026-02-24 08:21:05.428 | app | out |
2026-02-24 08:21:05.428 | app | err | ERROR / uvicorn.error / Application startup failed. Exiting.
2026-02-24 08:21:05.948 | ui | out | Redirecting to: http://127.0.0.1:9001/

Cursor diagnosed and fixed the error and summarized it:
The app now starts successfully.
Root cause: The app failed during startup because SqlConfig required warehouse_id, which is loaded from DATABRICKS_SQL_WAREHOUSE_ID. That variable was not set in .env, so Pydantic raised a validation error.
Changes made:
src/fast_wolf/backend/core/sql.py – warehouse_id now has a default of "", so the app can start without the env var. If a route uses Dependencies.Sql without a configured warehouse, it will return a 503 with a clear message.
.env – Added a commented example for DATABRICKS_SQL_WAREHOUSE_ID and instructions on how to obtain it.
To enable SQL features: Uncomment and set DATABRICKS_SQL_WAREHOUSE_ID in .env with your SQL warehouse ID (from Databricks: SQL Warehouses → select warehouse → copy ID from the URL).

[renardeinside]

hey @maucaro

Root cause: The app failed during startup because SqlConfig required warehouse_id, which is loaded from DATABRICKS_SQL_WAREHOUSE_ID. That variable was not set in .env, so Pydantic raised a validation error.
Changes made:
src/fast_wolf/backend/core/sql.py – warehouse_id now has a default of "", so the app can start without the env var. If a route uses Dependencies.Sql without a configured warehouse, it will return a 503 with a clear message.
.env – Added a commented example for DATABRICKS_SQL_WAREHOUSE_ID and instructions on how to obtain it.
To enable SQL features: Uncomment and set DATABRICKS_SQL_WAREHOUSE_ID in .env with your SQL warehouse ID (from Databricks: SQL Warehouses → select warehouse → copy ID from the URL).

The provided error clearly states that the env variable was not set in the .env file - what exactly is missing? Auto-selection of sql warehouse? I/O window when using the addon?

[maucaro]

@renardeinside , yes, apx init does not ask for the warehouse to use; it should do so similar to the way it asks for the profile to use. The code changes proposed by Cursor are still helpful, in my opinion, so even if DATABRICKS_SQL_WAREHOUSE_ID is not set in .env, it won't throw a runtime error.