Advanced grammar doesn't work with multi-platform (ST124) charms

[carlcsaposs-canonical]

Bug Description

Advanced grammar doesn't work with charms using ST124 syntax (https://docs.google.com/document/d/1QVHxZumruKVZ3yJ2C74qWhvs-ye5I9S6avMBDHs2YcQ/edit?pli=1&tab=t.0#heading=h.sn552414niwh)

To Reproduce

git clone https://github.com/canonical/mysql-router-operator/
cd mysql-router-operator
git checkout 4fde81baf3fcf710caa77ae7afcc0e5d51c855af
sudo snap install charmcraft --classic --channel latest/edge
charmcraft pack -v --platform [email protected]:amd64

Expected behavior

rustup is installed from snap on 22.04 base

Actual behavior

charmcraft attempts to install rustup with apt and fails

Starting charmcraft, version 3.2.2.post138+g33519b4a
Logging execution to '/home/ubuntu/.local/state/charmcraft/log/charmcraft-20250108-115236.624501.log'
Launching managed ubuntu 22.04 instance...
Creating new instance from remote
Creating new base instance from remote 
Creating new instance from base instance 
Starting instance 
Starting charmcraft, version 3.2.2.post138+g33519b4a
Logging execution to '/tmp/charmcraft.log'
Initialising lifecycle
Installing build-packages
Cannot find package listed in 'build-packages': rustup
Failed to execute charmcraft in instance.
Full execution log: '/home/ubuntu/.local/state/charmcraft/log/charmcraft-20250108-115236.624501.log'

Environment

Ubuntu 22.04

$ snap list
Name              Version                  Rev    Tracking            Publisher          Notes
charmcraft        3.2.2.post138+g33519b4a  5709   latest/edge         canonical✓         classic
core18            20240920                 2846   latest/stable       canonical✓         base
core20            20240911                 2434   latest/stable       canonical✓         base
core22            20241119                 1722   latest/stable       canonical✓         base
core24            20240920                 609    latest/stable       canonical✓         base
juju              3.6.1                    29241  3/stable            canonical✓         -
lxd               5.0.4-497fe1e            31333  5.0/stable/…        canonical✓         -
microk8s          v1.29.11                 7435   1.29-strict/stable  canonical✓         -
snapcraft         8.5.1                    13181  latest/stable       canonical✓         classic
snapd             2.66.1                   23258  latest/stable       canonical✓         snapd

charmcraft.yaml

# Copyright 2022 Canonical Ltd.
# See LICENSE file for licensing details.

type: charm
platforms:
  [email protected]:amd64:
  [email protected]:amd64:
  [email protected]:arm64:
  [email protected]:amd64:
# Files implicitly created by charmcraft without a part:
# - dispatch (https://github.com/canonical/charmcraft/pull/1898)
# - manifest.yaml
#   (https://github.com/canonical/charmcraft/blob/9ff19c328e23b50cc06f04e8a5ad4835740badf4/charmcraft/services/package.py#L259)
# Files implicitly copied/"primed" by charmcraft without a part:
# - actions.yaml, config.yaml, metadata.yaml
#   (https://github.com/canonical/charmcraft/blob/9ff19c328e23b50cc06f04e8a5ad4835740badf4/charmcraft/services/package.py#L290-L293
#   https://github.com/canonical/charmcraft/blob/9ff19c328e23b50cc06f04e8a5ad4835740badf4/charmcraft/services/package.py#L156-L157)
parts:
  # "poetry-deps" part name is a magic constant
  # https://github.com/canonical/craft-parts/pull/901
  poetry-deps:
    plugin: nil
    build-packages:
      - curl
    override-build: |
      # Use environment variable instead of `--break-system-packages` to avoid failing on older
      # versions of pip that do not recognize `--break-system-packages`
      PIP_BREAK_SYSTEM_PACKAGES=true python3 -m pip install --user --upgrade pip==24.3.1  # renovate: charmcraft-pip-latest

      # Use uv to install poetry so that a newer version of Python can be installed if needed by poetry
      curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/uv/releases/download/0.5.15/uv-installer.sh | sh  # renovate: charmcraft-uv-latest
      # poetry 2.0.0 requires Python >=3.9
      if ! "$HOME/.local/bin/uv" python find '>=3.9'
      then
        # Use first Python version that is >=3.9 and available in an Ubuntu LTS
        # (to reduce number of Python versions we use)
        "$HOME/.local/bin/uv" python install 3.10.12  # renovate: charmcraft-python-ubuntu-22.04
      fi
      "$HOME/.local/bin/uv" tool install --no-python-downloads --python '>=3.9' poetry==2.0.0 --with poetry-plugin-export==1.8.0  # renovate: charmcraft-poetry-latest

      ln -sf "$HOME/.local/bin/poetry" /usr/local/bin/poetry
  # "charm-poetry" part name is arbitrary; use for consistency
  # Avoid using "charm" part name since that has special meaning to charmcraft
  charm-poetry:
    # By default, the `poetry` plugin creates/primes these directories:
    # - lib, src
    #   (https://github.com/canonical/charmcraft/blob/9ff19c328e23b50cc06f04e8a5ad4835740badf4/charmcraft/parts/plugins/_poetry.py#L76-L78)
    # - venv
    #   (https://github.com/canonical/charmcraft/blob/9ff19c328e23b50cc06f04e8a5ad4835740badf4/charmcraft/parts/plugins/_poetry.py#L95
    #   https://github.com/canonical/craft-parts/blob/afb0d652eb330b6aaad4f40fbd6e5357d358de47/craft_parts/plugins/base.py#L270)
    plugin: poetry
    source: .
    after:
      - poetry-deps
    poetry-export-extra-args: ['--only', 'main,charm-libs']
    build-snaps:
      - on [email protected]:
          - rustup
      - on [email protected]:
          - rustup
    build-packages:
      - libffi-dev
      - libssl-dev
      - pkg-config
      - on [email protected]: []
      - on [email protected]: []
      - else:
          - rustup
    override-build: |
      rustup --version
      rustup default stable
      craftctl default
      # Include requirements.txt in *.charm artifact for easier debugging
      cp requirements.txt "$CRAFT_PART_INSTALL/requirements.txt"
  # "files" part name is arbitrary; use for consistency
  files:
    plugin: dump
    source: .
    build-packages:
      - git
    override-build: |
      # Workaround to add unique identifier (git hash) to charm version while specification
      # DA053 - Charm versioning
      # (https://docs.google.com/document/d/1Jv1jhWLl8ejK3iJn7Q3VbCIM9GIhp8926bgXpdtx-Sg/edit?pli=1)
      # is pending review.
      python3 -c 'import pathlib; import shutil; import subprocess; git_hash=subprocess.run(["git", "describe", "--always", "--dirty"], capture_output=True, check=True, encoding="utf-8").stdout; file = pathlib.Path("charm_version"); shutil.copy(file, pathlib.Path("charm_version.backup")); version = file.read_text().strip(); file.write_text(f"{version}+{git_hash}")'

      craftctl default
    prime:
      - LICENSE
      - charm_version
      - workload_version
      - templates

Relevant log output

charmcraft-20250108-115236.624501.log

[carlcsaposs-canonical]

I also tried

    build-packages:
      - on [email protected]:
          - libffi-dev
          - libssl-dev
          - pkg-config
      - on [email protected]:
          - libffi-dev
          - libssl-dev
          - pkg-config
      - else:
          - libffi-dev
          - libssl-dev
          - pkg-config
          - rustup

and

    build-packages:
      - on [email protected]:amd64:
          - libffi-dev
          - libssl-dev
          - pkg-config
      - on [email protected]:amd64:
          - libffi-dev
          - libssl-dev
          - pkg-config
      - else:
          - libffi-dev
          - libssl-dev
          - pkg-config
          - rustup

and

    build-packages:
      - libffi-dev
      - libssl-dev
      - pkg-config
      - on [email protected]:amd64: []
      - on [email protected]:amd64: []
      - else:
          - rustup

but got the same results

[mr-cal]

This is expected as it's not implemented yet. Charmcraft doesn't officially support advanced grammar and craft-grammar doesn't support using the platform in grammar statements.

We have tasks outlined but I don't think we have an ETA.

[carlcsaposs-canonical]

thank you for the information!