I've created a package with no particular requirements for Python version, when I create conda environment with Python 3.8, it tells me that it will only install if I change my Python version to anything else, but Python 3.8, when I try it with 3.9, for example, then it tells me that that my package can only be installed if my Python version is 3.8.
Needless to say that --no-deps does nothing in this context. When I look up the metadata from the package.tar.bz2, I can see that conda added a bunch of requirements that were never there (in particular, it added Python version).
Below is a truly idiotic error message I was able to solicit from conda, which, essentially, claims that everything is honky-dory, but it fails anyways:
Collecting package metadata (current_repodata.json): ...working... Unable to retrieve repodata (response: 404) for https://conda.anaconda.org/<snip>/linux-64/current_repodata.json
done
Solving environment: ...working... failed with initial frozen solve. Retrying with flexible solve.
Solving environment: ...working... failed with repodata from current_repodata.json, will retry with next repodata source.
Collecting package metadata (repodata.json): ...working... done
Solving environment: ...working... failed with initial frozen solve. Retrying with flexible solve.
Solving environment: ...working...
Found conflicts! Looking for incompatible packages.
This can take several minutes. Press CTRL-C to abort.
failed
Traceback (most recent call last):
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/cli/install.py", line 261, in install
unlink_link_transaction = solver.solve_for_transaction(
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/core/solve.py", line 114, in solve_for_transaction
unlink_precs, link_precs = self.solve_for_diff(update_modifier, deps_modifier,
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/core/solve.py", line 157, in solve_for_diff
final_precs = self.solve_final_state(update_modifier, deps_modifier, prune, ignore_pinned,
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/core/solve.py", line 281, in solve_final_state
ssc = self._run_sat(ssc)
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/common/io.py", line 88, in decorated
return f(*args, **kwds)
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/core/solve.py", line 815, in _run_sat
ssc.solution_precs = ssc.r.solve(tuple(final_environment_specs),
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/common/io.py", line 88, in decorated
return f(*args, **kwds)
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/resolve.py", line 1320, in solve
raise UnsatisfiableError({})
conda.exceptions.UnsatisfiableError:
Did not find conflicting dependencies. If you would like to know which
packages conflict ensure that you have enabled unsatisfiable hints.
conda config --set unsatisfiable_hints True
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/exceptions.py", line 1079, in __call__
return func(*args, **kwargs)
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/cli/main.py", line 84, in _main
exit_code = do_call(args, p)
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/cli/conda_argparse.py", line 83, in do_call
return getattr(module, func_name)(args, parser)
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/cli/main_install.py", line 20, in execute
install(args, parser, 'install')
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/cli/install.py", line 308, in install
raise e
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/cli/install.py", line 295, in install
unlink_link_transaction = solver.solve_for_transaction(
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/core/solve.py", line 114, in solve_for_transaction
unlink_precs, link_precs = self.solve_for_diff(update_modifier, deps_modifier,
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/core/solve.py", line 157, in solve_for_diff
final_precs = self.solve_final_state(update_modifier, deps_modifier, prune, ignore_pinned,
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/core/solve.py", line 275, in solve_final_state
ssc = self._add_specs(ssc)
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/core/solve.py", line 704, in _add_specs
ssc.r.find_conflicts(spec_set)
File "/home/wvxvw/anaconda3/lib/python3.8/site-packages/conda/resolve.py", line 352, in find_conflicts
raise UnsatisfiableError(bad_deps, strict=strict_channel_priority)
conda.exceptions.UnsatisfiableError: The following specifications were found
to be incompatible with the existing python installation in your environment:
Specifications:
- <snip> -> python[version='>=2.7,<2.8.0a0|>=3.5,<3.6.0a0|>=3.6,<3.7.0a0|>=3.7,<3.8.0a0|>=3.9,<3.10.0a0']
Your python: python=3.8
If python is on the left-most side of the chain, that's the version you've asked for.
When python appears to the right, that indicates that the thing on the left is somehow
not available for the python version you are constrained to. Note that conda will not
change your python version to a different minor version unless you explicitly specify
that.
By the way, I did enable reporting of unsatisfiable dependencies, but it doesn't matter.