Demo build fails with "Non-conda folder exists at prefix"

[eikimart]

Description

I'm trying to install voici using mamba. I get as far as running the demo, which fails with the following. I've duplicated this on two ubuntu installations and on windows.

error libmamba Non-conda folder exists at prefix
critical libmamba Aborting.
[VoiciBuildApp] ERROR | [lite] [post_build] [jupyterlite-xeus] [ERR] Command '['/home/eiki/miniforge3/bin/mamba', 'create', '--yes', '--prefix', PosixPath('/tmp/tmpraf_7j_u/env/envs/voici'), '-c', 'https://repo.prefix.dev/emscripten-forge-dev', '-c', 'https://repo.prefix.dev/conda-forge']' returned non-zero exit status 1.
Traceback (most recent call last):
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/doit_cmd.py", line 294, in run
return command.parse_execute(args)
^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/cmd_base.py", line 150, in parse_execute
return self.execute(params, args)
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/cmd_base.py", line 570, in execute
return self._execute(**exec_params)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/cmd_run.py", line 265, in _execute
return runner.run_all(self.control.task_dispatcher())
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/runner.py", line 254, in run_all
self.run_tasks(task_dispatcher)
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/runner.py", line 213, in run_tasks
node = task_dispatcher.generator.send(node)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/control.py", line 629, in _dispatcher_generator
next_step = node.step()
^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/control.py", line 336, in step
return next(self.generator)
^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/control.py", line 345, in _func
for value in decorated(*args, **kwargs):
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/control.py", line 473, in _add_task
new_tasks = generate_tasks(to_load, task_gen, ref.doc)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/loader.py", line 390, in generate_tasks
for task_dict, x_doc in flat_generator(gen_result, gen_doc):
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/doit/loader.py", line 27, in flat_generator
for item in gen:
^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_core/manager.py", line 138, in _delayed_gather
yield from _gather()
File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_core/manager.py", line 131, in _gather
raise error
File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_core/manager.py", line 123, in _gather
for task in getattr(addon, attr)(self):
^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_xeus/add_on.py", line 138, in post_build
self.create_prefix()
File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_xeus/add_on.py", line 162, in create_prefix
create_conda_env_from_env_file(root_prefix, yaml_content, env_file.parent)
File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_xeus/create_conda_env.py", line 53, in create_conda_env_from_env_file
create_conda_env_from_specs(
File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_xeus/create_conda_env.py", line 69, in create_conda_env_from_specs
_create_conda_env_from_specs_impl(
File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_xeus/create_conda_env.py", line 126, in _create_conda_env_from_specs_impl
return _create_env_with_config(MAMBA_COMMAND, prefix_path, specs, channels_args)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_xeus/create_conda_env.py", line 139, in _create_env_with_config
subprocess_run(
File "/home/eiki/miniforge3/lib/python3.12/subprocess.py", line 571, in run
raise CalledProcessError(retcode, process.args,
subprocess.CalledProcessError: Command '['/home/eiki/miniforge3/bin/mamba', 'create', '--yes', '--prefix', PosixPath('/tmp/tmpraf_7j_u/env/envs/voici'), '-c', 'https://repo.prefix.dev/emscripten-forge-dev', '-c', 'https://repo.prefix.dev/conda-forge']' returned non-zero exit status 1.

Reproduce

mamba install -c conda-forge voici

Followed by:

voici notebooks/

in the demos/ directory.

Expected behavior

Demos should build.

Context

Tested on Ubuntu 24.04.2 LTS
Tested on Ubuntu 24.04.5 LTS
Tested on Windows 10.

[jtpio]

Thanks @eikimart for the report.

Seeing the following:

File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_xeus/create_conda_env.py", line 69, in create_conda_env_from_specs
_create_conda_env_from_specs_impl(
File "/home/eiki/miniforge3/lib/python3.12/site-packages/jupyterlite_xeus/create_conda_env.py", line 126, in _create_conda_env_from_specs_impl
return _create_env_with_config(MAMBA_COMMAND, prefix_path, specs, channels_args)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Wondering if this could be an issue with jupyterlite-xeus (https://github.com/jupyterlite/xeus) ? Which I believe still requires micromamba at the moment?

Otherwise to debug this more, maybe you could try to uninstall jupyterlite-xeus, and use jupyterlite-pyodide-kernel instead, just to see if the build works?