Install command 'pip install buckaroo[xorq]' silently no-ops; sidecar then fails to import tornado

[paddymul]

Bug

buckaroo-tauri (this org's Tauri plugin) instructs users to install the Python sidecar via:

pip install 'buckaroo[xorq]'

(buckaroo-tauri README README.md:69 and examples/tauri-app/README.md.)

But buckaroo==0.13.5 has no xorq extra. Available extras: dev, jupyterlab, marimo, mcp, notebook, packaging-tools, polars, test. pip and uv both install base buckaroo and emit only a one-line warning that's easy to miss in CI / scrollback:

warning: The package `buckaroo==0.13.5` does not have an extra named `xorq`

tornado (gated under [mcp]) is therefore not installed. The sidecar then crashes on first launch:

$ python -m buckaroo.server --help
ModuleNotFoundError: No module named 'tornado'

The same trap applies to pip install 'buckaroo[pandas]', also referenced in the tauri README — no pandas extra exists either.

Repro

uv venv --python 3.12 /tmp/repro && cd /tmp/repro
./bin/uv pip install 'buckaroo[xorq]'  # warning → ignored extra
./bin/python -m buckaroo.server --help  # ModuleNotFoundError: tornado

vs. working path:

./bin/uv pip install 'buckaroo[mcp]'
./bin/python -m buckaroo.server --help  # usage: server.py [-h] [--port ...] ...

Why this is a buckaroo bug, not just a buckaroo-tauri docs slip

The instruction lives in this org's own Tauri integration, paired with a Rust API (BuckarooConfig::xorq(), BuckarooConfig::pandas()) that documents what backend the user is opting into. The Python-side extras should be the install-time mirror of those backend presets. They aren't, so the two surfaces have drifted.

Fixing this on the Python side (this repo) is the right place because:

1. pip install 'buckaroo[xorq]' is a reasonable instinct any user will reach for given the Rust API — and it will keep being a reasonable instinct.
2. The silent-warning + delayed-crash failure mode is worse than a hard "no such extra" error. Most users will believe the install succeeded.
3. Editing the buckaroo-tauri README alone is the symptom fix, not the root fix — see closed Docs recommend non-existent 'buckaroo[xorq]' extra; sidecar fails to import tornado buckaroo-tauri#1.

Suggested resolutions (one of)

• Preferred: add xorq (and pandas) extras that pull tornado plus any backend-specific deps. This is exactly what Add 'xorq' install extra to match BuckarooConfig::xorq() preset #750 proposes — close this as a duplicate of Add 'xorq' install extra to match BuckarooConfig::xorq() preset #750 if you prefer the feature-request framing.
• Alternative: if [mcp] is intentionally the canonical name, raise the install-instruction inconsistency to a hard error — e.g. emit a UserWarning from buckaroo/__init__.py when imported without tornado available, telling the user to pip install 'buckaroo[mcp]'. Silent-degrade is the failure mode here.
• Docs-only fallback: if neither fix lands, update the buckaroo-tauri READMEs in lockstep with whatever extras name is authoritative.

Cross-ref: #750 (the "add xorq extra" feature request), buckaroo-data/buckaroo-tauri#1 (closed, redirected here).

[paddymul]

Correction / update after reading main:

The xorq extra does exist on main — added in 4b698cc (PR #691, 2026-05-05). Not yet released (latest PyPI is still 0.13.5).

However, the released-then-still-broken-for-tauri picture is what makes this issue worth keeping open. The current main definition is:

```toml

Install for the XorqStatPipeline. The pipeline operates on xorq

expressions (xorq.vendor.ibis) only — no raw ibis-framework dep.

xorq = [
"xorq>=0.1.0 ; python_version < '3.14'",
]
```

The scope comment makes the intent explicit: this extra is for the XorqStatPipeline Python-side feature, not the tauri sidecar. It does not pull tornado, so once 0.13.6 ships:

```sh
pip install 'buckaroo[xorq]'
python -m buckaroo.server --help

still: ModuleNotFoundError: No module named 'tornado'

```

The buckaroo-tauri install instruction (pip install 'buckaroo[xorq]') will therefore still be broken for its actual use case after the next release.

Updated suggested fixes

• Make [xorq] a superset that also pulls tornado. The XorqStatPipeline users get a few extra KB of tornado they don't need, but the install instruction in the canonical Tauri integration becomes correct. Lowest-friction option.
• Or: introduce a [tauri] extra that pulls tornado plus whatever else the sidecar needs, and update buckaroo-tauri docs to recommend pip install 'buckaroo[tauri]' (optionally with ,xorq for stat pipeline). This is the cleanest separation of concerns.
• Or: keep [xorq] scoped to stat-pipeline-only, and update buckaroo-tauri docs to recommend pip install 'buckaroo[xorq,mcp]'. Works, but the composite is non-obvious — most users will reach for [xorq] alone.

Either way, the silent-warning failure mode for the un-released current state remains the central bug.

[paddymul]

Decided direction (from offline discussion):

Add a [tauri-essentials] extra to buckaroo. Keep [xorq] scoped to the stat-pipeline (no tornado).

Rationale for the name:

• [tauri] is wrong — this isn't the Tauri shim itself (that lives in buckaroo-data/buckaroo-tauri), and it has nothing to do with the Tauri framework as a dependency.
• [tauri-essentials] signals "the Python runtime deps the Tauri integration needs to function" — i.e. the sidecar server stack, gated behind one install entry so users following the buckaroo-tauri README get a working sidecar in one command.

Proposed contents (sketch — to be refined in PR):

```toml
tauri-essentials = [
"tornado>=6.0",
# add anything else buckaroo.server depends on at runtime
# that isn't already in the base install
]
```

Follow-ups:

• buckaroo-tauri README to switch pip install 'buckaroo[xorq]' → pip install 'buckaroo[tauri-essentials]' (and [pandas] → drop or replace, since that doesn't exist either).
• [xorq] extra stays as-is (stat pipeline only).
• Worth a follow-up audit of buckaroo.server's actual import graph to make sure tornado is the only sidecar-only dep — anything else currently being pulled in by [mcp] that the sidecar relies on should be mirrored into [tauri-essentials].