[bug] ConanAPI: inspect fails

[tbsuht]

Environment details

• Operating System+version: -
• Compiler+version: -
• Conan version: 2.0.7
• Python version: 3.11.2

I'm trying to use the python ConanAPI, which fails with the following error.

Steps to reproduce

from conan.api.conan_api import ConanAPI
from conans.model.recipe_ref import RecipeReference
conan = ConanAPI()
conan.local.inspect(conan.cache.export_path(RecipeReference.loads("zlib/1.2.13")), [], None)

I think the package reference doesn't matter, use one from your local cache.

Logs

Traceback (most recent call last):
  File "/opt/venv/lib/python3.11/site-packages/conans/client/loader.py", line 313, in load_python_file
    loaded = imp_util.module_from_spec(spec)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 570, in module_from_spec
AttributeError: 'NoneType' object has no attribute 'loader'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/venv/lib/python3.11/site-packages/conans/client/loader.py", line 55, in load_basic_module
    module, conanfile = parse_conanfile(conanfile_path)
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.11/site-packages/conans/client/loader.py", line 288, in parse_conanfile
    module, filename = load_python_file(conanfile_path)
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.11/site-packages/conans/client/loader.py", line 351, in load_python_file
    raise ConanException("Unable to load conanfile in %s\n%s" % (conan_file_path,
conans.errors.ConanException: Unable to load conanfile in /home/user/.conan2/p/zlib15353192ba4c5/e
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 570, in module_from_spec
AttributeError: 'NoneType' object has no attribute 'loader'


During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/opt/venv/lib/python3.11/site-packages/conan/api/subapi/local.py", line 109, in inspect
    conanfile = app.loader.load_named(conanfile_path, name=None, version=None,
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.11/site-packages/conans/client/loader.py", line 98, in load_named
    conanfile, _ = self.load_basic_module(conanfile_path, graph_lock, remotes=remotes,
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/venv/lib/python3.11/site-packages/conans/client/loader.py", line 79, in load_basic_module
    raise ConanException("Error loading conanfile at '{}': {}".format(conanfile_path, e))
conans.errors.ConanException: Error loading conanfile at '/home/user/.conan2/p/zlib15353192ba4c5/e': Unable to load conanfile in /home/user/.conan2/p/zlib15353192ba4c5/e
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen importlib._bootstrap>", line 570, in module_from_spec
AttributeError: 'NoneType' object has no attribute 'loader'

[AbrilRBS]

Hi @tbsuht thanks a lot for your question.
As you can see, the API is currently not extensively documented, and this is on purpose - it allows us to have a bit more leeway to stabilize the API until we are happy with it.

Having said that, checking how the CLI uses these methods is usually a good starting point. In this case, the inspect() method is used here. As you can see, this needs to be passed a path to a conanfile.py, while the export method you called returns a folder.

You would probably need to do something like this (Not tested, might not actually work/the syntax might be a bit off, and please do not use it as public documentation!)

    export_path = conan_api.cache.export_path(RecipeReference.loads(ref))
    path = conan_api.local.get_conanfile_path(export_path, os.getcwd(), py=True)
    conanfile = conan_api.local.inspect(path, remotes=[], lockfile=None)

Let me know if that helps! :)

[tbsuht]

hi @RubenRBS

thanks, that's working! Don't know whether it makes sense to improve the API to be able to also work with a path to a directory, so that calling get_conanfile_path is not necessary (is then done internally). And of course it shouldn't crash with an exception, but tell me that my path was not providing a conanfile. :)