monata-sim-env

Monata Simulation Environment

Goal

Create a project-local pixi environment that can import monata from PyPI, run the current Monata simulator backend through ngspice, and provide OpenVAF/OSDI tooling for model flows.

Rules

• Keep external simulator binaries outside the Monata Python package.
• Own Monata user-environment orchestration: detect required tools, reuse or request package builds, create/update the project pixi environment, install PyPI monata, and verify runtime commands.
• Do not own recipe maintenance or raw rattler-build operations; delegate those to the conda-build skill.
• Prefer a user-owned local conda channel for circuit-tool packages.
• Require the user prompt to include an explicit CONDA_BUILD_OUTPUT_DIR=... value, or another explicit final channel directory. Do not invent one.
• If the user did not provide the final channel directory, ask for it and stop before running any build, pixi, or install commands.
• Inspect the current Monata workspace before choosing tool packages. Prefer scripts/detect_monata_tools.py from this skill; otherwise read pyproject.toml, README.md, src/, tests/, and docs/.
• Build the smallest package set needed for the requested Monata workflow. The current Monata baseline is ngspice plus openvaf-r.
• If the user-provided channel already contains the detected packages, skip the build and do not require rattler-build.
• Do not build every circuit-toolchain package, run --all, or build the Xyce recipe stack unless the user explicitly asks for those tools.
• Do not silently install host tools. If pixi is missing, stop and ask the user to install it or approve a specific install command. If rattler-build is missing and packages must be built, ask before installing it as a global CLI with pixi global install --channel https://prefix.dev/conda-forge rattler-build.
• Treat the setup request as permission to create/update the project pixi environment and install project dependencies. It is not permission to install global or host-level tools.
• Do not publish, upload, or authenticate to remote package channels.
• Use the conda-build skill for rattler-build details when it is installed. If it is not installed, tell the user to install conda-build from the same lizhangmai/skills marketplace or skill source before building packages.

Workflow

1. Inspect the current directory and decide where the pixi project should live. Use the current directory when the user is already inside the intended project directory, including directories named test. Do not create a nested monata-work/ directory unless the user explicitly asks for a new subdirectory.

2. Check for python3, git, and pixi. If pixi is missing, stop before environment setup and ask the user to install pixi or approve a specific install command.

3. Read the user-provided final channel directory and set:

   export CONDA_BUILD_OUTPUT_DIR="<user-provided-absolute-conda-channel>"
   

4. Detect the required circuit-tool packages from the Monata workspace:

   python3 scripts/detect_monata_tools.py --root "<project-workspace>" --format shell
   

   Run this from the installed or cloned monata-sim-env skill directory. If a Monata workspace cannot be inspected, use the current baseline package set: ngspice openvaf-r.

5. Check the user-provided channel. If all detected packages are present, skip the build step:

   python3 scripts/rattler_channel.py check-channel \
     --recipe-set circuit-toolchain \
     --package ngspice \
     --package openvaf-r
   

   Run this from the installed or cloned conda-build skill directory. Use the detector output instead of hard-coding this list when the workspace indicates a different package set.

6. If any detected package is missing, build only missing work from the circuit-toolchain recipe set and let existing artifacts be reused:

   python3 scripts/rattler_channel.py build \
     --recipe-set circuit-toolchain \
     --package ngspice \
     --package openvaf-r \
     --skip-existing
   

   If rattler-build is missing but pixi is available, ask before installing it globally:

   pixi global install --channel https://prefix.dev/conda-forge rattler-build
   rattler-build --version
   

7. Create or update the pixi environment in the selected project directory with the local channel first. If pixi.toml already exists, skip pixi init and run only the pixi add commands. If it does not exist, initialize the current directory:

   pixi init . \
     --channel "file://$CONDA_BUILD_OUTPUT_DIR" \
     --channel https://prefix.dev/conda-forge
   pixi add python=3.12 ngspice openvaf-r
   pixi add --pypi monata
   

8. Verify:

   pixi run python - <<'PY'
   import shutil
   import monata
   
   print(monata.__name__)
   print(shutil.which("ngspice"))
   print(shutil.which("openvaf-r"))
   PY
   pixi run ngspice --version
   pixi run openvaf-r --help
   

Existing Simulator Environment

If the user already has the detected circuit tools installed in the active environment, skip the local channel build and install only Monata:

python -m pip install monata
python -c "import shutil; print(shutil.which('ngspice')); print(shutil.which('openvaf-r'))"

Use this shortcut only when the required executables are already on PATH or under CONDA_PREFIX/bin.

Optional Packages

Build additional circuit packages only when the user explicitly asks for a workflow that needs them:

• xyce: deferred Monata backend work or external Xyce workflows; build the recipe stack with --up-to xyce only for those explicit requests.

• monata-techlib: install from PyPI only when first-party technology metadata is needed:

  pixi add --pypi monata-techlib