conan-1.6-utilities/CLAUDE.md

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# CLAUDE.md
Guidance for working on this repository. It records decisions made when the
project was started (August 2026) that are not obvious from the code.
## What this is
Small single-file Python utilities for **Conan 1.x, targeting 1.66**. Not
Conan 2. The first (and so far only) tool is `conandeps.py`; see `README.md`
for what it does and how it is used.
## Hard constraints
- **Conan 1.66 only.** Use the `conans.client.conan_api.ConanAPIV1` API and
Conan 1 graph internals (`Node.binary`, `Node.dependencies`,
`conanfile.requires`). Do not introduce Conan 2 APIs or a Conan 2 code path.
- **Python 3.83.11.** Conan 1.x imports the `imp` module, which is gone in
3.12. `requires-python` in `pyproject.toml` and the PEP 723 header in
`conandeps.py` both say `<3.12`; keep them in sync.
- **All development runs inside the container.** Use `./dev.sh <cmd>` for
every python/pytest/ruff/uv invocation. Never run `conan` against the
host's `~/.conan`; never `pip install` on the host. Rebuild the image with
`./dev.sh build` after touching `Containerfile`.
- **Never depend on the private remote.** The real remote is called `knor`
and only exists on the machine where the tool is used. Tests must use the
local `conan_server` fixture in `tests/test_conandeps.py`.
## Design decisions (and why)
- **Binary availability is computed via Conan's graph, not `conan search`.**
The graph is built once per build type through `ConanAPIV1.info()` and each
node's `binary` status is read. This honours `package_id()` overrides,
options and `default_package_id_mode` exactly like `conan install`. Do not
replace this with settings-dict matching against `conan search` output.
- **"Missing" means missing for the exact profile.** Not "no binary with
that build_type at all".
- **Overrides are parsed from Conan's WARN output.** Conan 1 does not record
overrides on the graph; `Requirements.update()` mutates `req.ref` in place
and only emits `"<pkg>: requirement <old> overridden by <who> to <new>"`.
`conandeps` captures the output stream with a non-coloured `ConanOutput`
and matches `_OVERRIDE_RE`. `test_overrides` pins this format if a Conan
patch release changes the wording, that test is the alarm.
- **Both explicit and implicit overrides are reported.** `override=True`
requirements are collected from `conanfile.requires` to label an override
as explicit; everything else parsed from the WARN lines is implicit.
- **`range_ref` is not a version range after an override.** Conan reuses
`Requirement.range_ref` to hold the pre-override reference, so only treat
it as a range when `req.version_range` is truthy.
- **Single file, stdlib + Conan only.** No third-party deps beyond Conan.
Packaging is hatchling with `only-include = ["conandeps.py"]`; the PEP 723
header makes the file usable via `uv run conandeps.py` without a checkout.
- **Exit codes:** `0` fine, `1` missing binaries, `2` Conan error. CI relies
on this.
## Workflow
- Lint/format: `./dev.sh ruff check .` and `./dev.sh ruff format .`
(config in `pyproject.toml`, target py38, line length 100). Run
`shellcheck dev.sh` after editing the wrapper.
- Tests: `./dev.sh python -m pytest`. The fixture spins up `conan_server`
on a free port with a pre-written `server.conf` (the port cannot be given
on the command line), creates fake packages whose `build()` does nothing,
uploads them, then wipes the cache so binaries can only come from the
remote. Fake recipes need `--build=missing` at create time because
dependencies' binaries are deliberately incomplete.
- Dependencies: `uv.lock` is committed; regenerate with `./dev.sh uv lock`
after changing `pyproject.toml`.
- Commits: atomic, no `--amend`; run ruff + pytest + shellcheck before
committing. Add a memory of anything a future session could not derive
from the repository.
## Adding another tool
Follow the `conandeps.py` pattern: one executable file with a module
docstring explaining *how* and *why*, a PEP 723 header, a `main(argv)` that
returns an exit code, a `[project.scripts]` entry, an `only-include` entry in
`pyproject.toml`, tests under `tests/` using the shared `conan_env` fixture,
and a section in `README.md`.