Building from source

Python package (the normal path)

StormWeaver ships as a Python extension module built with scikit-build-core + nanobind, using Conan 2 to fetch C++ dependencies. Everything needed is driven through uv:

uv python install 3.14t
uv venv
uv pip install -e . --group dev

uv pip install -e . invokes CMake/Conan under the hood and rebuilds the extension whenever sources change. task setup runs the same steps plus pre-commit install. task build re-runs just the editable install.

Conan profile

The first build needs a Conan profile:

conan profile detect --exist-ok

StormWeaver requires C++23, and gcc >= 15 defaults its C compiler to C23 (which breaks libpq's typedef bool). Both are handled by conan/host.profile, checked into the repo and wired in automatically by cmake/conan_setup.cmake - no manual profile editing needed, on any machine.

Pure C++ builds (no Python)

For core development (no Python bindings), use the CMake presets in CMakePresets.json directly:

cmake --preset debug
cmake --build --preset debug
ctest --preset debug

or via Taskfile: task cpp:build / task cpp:test (set PRESET=asan-ubsan or PRESET=tsan to switch presets).

Available presets: debug, asan-ubsan (address + undefined behavior sanitizers), tsan (thread sanitizer). These build with WITH_PYTHON=OFF, so bindings/module.cpp is not part of this build - use the uv pip install -e . path to build the Python module, optionally with CMAKE_ARGS="-DWITH_ASAN=ON -DWITH_UBSAN=ON" for a sanitized extension build.

Taskfile targets

Task	What it does
`task setup`	uv python install + venv + editable install + pre-commit hooks
`task build`	Rebuild the extension + package
`task cpp:build`	Pure C++ build (`PRESET=debug\\|asan-ubsan\\|tsan`)
`task cpp:test`	ctest for the pure C++ build
`task test:py`	Python unit tests (`pytest tests/unit`)
`task test:scenario:basic`	Runs `scenarios/ci/basic.py` end to end (needs `PG_DIR`)
`task test`	cpp:test + test:py + test:scenario:basic
`task fmt`	Autofix formatting (clang-format, ruff format + fix)
`task fmt:check`	Check-only formatting
`task tidy`	clang-tidy over `core/src`
`task lint`	fmt:check + mypy
`task clean`	Remove `build/` and `dist/`

Scenario tasks need PG_DIR — a PostgreSQL installation containing bin/initdb. Pass it per invocation (task test:scenario:basic PG_DIR=/usr/lib/postgresql/17) or set it once in a gitignored .env file at the repo root (PG_DIR=/usr/lib/postgresql/17).

Quality gates

task fmt, task lint, task tidy, and task test are also what CI runs: a lint job, a debug/asan-ubsan/tsan matrix, the basic scenario, the asan scenario, and the determinism check (scenarios/ci/determinism.py). Pre-commit hooks run a subset of the same checks locally on commit.