pywavelets-feedstock failed to parse

[rgommers]

What happened?

Trying conda-recipe-manager convert on https://github.com/conda-forge/pywavelets-feedstock/ resulted in an obscure error message:

$ conda-recipe-manager convert ./recipe/meta.yaml
EXCEPTION: An exception occurred while parsing the recipe file
pop from empty list
0 errors and 0 warnings were found.

To Reproduce

Steps to reproduce the behavior:

1. git clone git@github.com:conda-forge/pywavelets-feedstock.git
2. cd pywavelets-feedstock
3. conda-recipe-manager convert ./recipe/meta.yaml

Additional Details (please complete the following information):

• OS: Linux x86-64
• Conda Recipe Manager version 0.3.4 from conda-forge

[schuylermartin45]

Thank you for reporting this! I can't find an existing ticket for this error.

I haven't tested this, but looking at the recipe file, my guess is that the issue lies with:

    - pip check
    {% set label = "'full'" %}
    {% set tests = "['pywt']" %}
    - python -c "import sys; import pywt; sys.exit(not pywt.test(verbose=2, label={{ label }}, tests={{ tests }}, extra_argv=['--durations=50', '-k', 'not (test_mra_axis or test_mra2_axes or test_mra2_roundtrip or test_iswtn_mixed_dtypes)']))"

Those variables are already set at the top of the file, so I assume they are safe to remove here on lines 52-53.

If that doesn't solve the issue, I don't think the parser currently supports JINJA list variables. That might take some time to implement. In my experience, it is relatively uncommon to see that in a recipe file, so it hasn't come up yet.

In the mean time, you could attempt to comment/delete those lines and add them back in, post-conversion. That should at least alleviate some of the manual conversion effort.

I'm going to capture the file here for ease of discovery, if those suggestions end up working for you.

{% set label = "'full'" %}
{% set tests = "['pywt']" %}
{% set name = "pywavelets" %}
{% set version = "1.7.0" %}

package:
  name: {{ name|lower }}
  version: {{ version }}

source:
  url: https://pypi.io/packages/source/{{ name[0] }}/{{ name }}/{{ name }}-{{ version }}.tar.gz
  sha256: b47250e5bb853e37db5db423bafc82847f4cde0ffdf7aebb06336a993bc174f6

build:
  number: 2
  skip: true  # [py<310]
  script:
    - mkdir builddir
    - {{ PYTHON }} -m mesonbuild.mesonmain setup $MESON_ARGS builddir   # [unix]
    - {{ PYTHON }} -m mesonbuild.mesonmain setup %MESON_ARGS% builddir  # [win]
    - {{ PYTHON }} -m build --wheel --no-isolation --skip-dependency-check -Cbuilddir=builddir
    - {{ PYTHON }} -m pip install --find-links dist pywavelets

requirements:
  build:
    - python                                 # [build_platform != target_platform]
    - cross-python_{{ target_platform }}     # [build_platform != target_platform]
    - cython >=3.0.4                         # [build_platform != target_platform]
    - numpy                                  # [build_platform != target_platform]
    - ninja                                  # [unix]
    - {{ compiler('c') }}
    - {{ stdlib('c') }}
  host:
    - python
    - python-build
    - pip
    - cython >=3.0.4
    - numpy
    - meson-python >=0.16.0
  run:
    - numpy >=1.23,<3
    - python

test:
  requires:
    - pytest
    - pip
  imports:
    - pywt
  commands:
    - pip check
    {% set label = "'full'" %}
    {% set tests = "['pywt']" %}
    - python -c "import sys; import pywt; sys.exit(not pywt.test(verbose=2, label={{ label }}, tests={{ tests }}, extra_argv=['--durations=50', '-k', 'not (test_mra_axis or test_mra2_axes or test_mra2_roundtrip or test_iswtn_mixed_dtypes)']))"

about:
  home: https://github.com/PyWavelets/pywt
  license: MIT
  license_file: LICENSE
  summary: Discrete Wavelet Transforms in Python

extra:
  recipe-maintainers:
    - grlee77
    - jakirkham
    - ocefpaf
    - rgommers

[rgommers]

Those variables are already set at the top of the file, so I assume they are safe to remove here on lines 52-53.

That is indeed the issue, thanks!

In my experience, it is relatively uncommon to see that in a recipe file, so it hasn't come up yet.

The same issue is present also in the numpy and scipy feedstocks, so I suspect there's at least one fairly prolific recipe author who made a habit of using this pattern.