I'm getting a super strange result that I can't make sense of.

black<23.13.0,>=23.12 black[jupyter]<23.13.0,>=23.12

ERROR: Cannot install black<23.13.0 and >=23.12 and black[jupyter]==23.12.1 because these package versions have conflicting dependencies.

 The conflict is caused by:
     The user requested black<23.13.0 and >=23.12
     black[jupyter] 23.12.1 depends on black 23.12.1

Anyone know why this would be happening when generating a lockfile via pants?

Please provide the input requirements that reproduce this, ideally in a small github repo (so that we also have the pants.toml etc)

unfortunately it's in a private repo with 8 separate pyproject.toml in a single resolve. I can provide this though

$ egrep -i "^\s*(black)\s*=" ./**/pyproject.toml -h | sort -u
black = "~23.12"
black = { version = "~23.12", optional = true }
black = { extras = ["jupyter"], version = "~23.12"}

I'd recommend creating a public repo containing just the relevant bits, without anything private. It is much easier to offer help when we can just clone a repo and run a command to reproduce a potential problem, rather than having to reverse engineer it in bits and bobs.

Does this help or do you need the actual underlying pyproject.toml files?

08:37:28.06 [ERROR] 1 Exception encountered:

Engine traceback:
  in `generate-lockfiles` goal

ProcessExecutionFailure: Process 'Generate lockfile for <redacted>' failed with exit code 1.
stdout:

stderr:
pid 55613 -> /Users/jasonbarnett/.cache/pants/named_caches/pex_root/venvs/df773647d6083b93c874a7ce1b736a536cac4192/bf23592afc6bbf9e59da204a4c864270f9819638/bin/python -sE /Users/jasonbarnett/.cache/pants/named_caches/pex_root/venvs/df773647d6083b93c874a7ce1b736a536cac4192/bf23592afc6bbf9e59da204a4c864270f9819638/pex --disable-pip-version-check --no-python-version-warning --exists-action a --no-input --isolated -q --cache-dir /Users/jasonbarnett/.cache/pants/named_caches/pex_root/pip/23.1.2/pip_cache --log /private/var/folders/kw/qhf2k3js3nvgf7t8_1g46skm0000gq/T/pants-sandbox-2Q3q32/.tmp/pex-pip-log.0h6sqanc/pip.log download --dest /private/var/folders/kw/qhf2k3js3nvgf7t8_1g46skm0000gq/T/pants-sandbox-2Q3q32/.tmp/tmpartiq2qb/opt.homebrew.Cellar.python@3.9.3.9.18_1.Frameworks.Python.framework.Versions.3.9.bin.python3.9 PyYAML<7.0.0,>=6.0 SQLAlchemy<2.0.0,>=1.4 aiohttp<4.0.0,>=3.8.4 aiohttp[speedups]<4.0.0,>=3.8.3 alembic<2.0.0,>=1.8.0 artifacts-keyring authlib<2.0.0,>=1.2 azure-core<2.0.0,>=1.25.0 azure-storage-blob<13.0.0,>=12.16.0 black<23.13.0,>=23.12 black[jupyter]<23.13.0,>=23.12 bleach<7.0.0,>=6.0.0 boto3<2.0.0,>=1.18 boto3<2.0.0,>=1.26.122 boto3<2.0.0,>=1.26.58 boto3>=1.26.123 botocore<2.0.0,>=1.25.11 cachetools<6.0.0,>=5.2.0 cachetools<6.0.0,>=5.3.0 cachetools<6.0.0,>=5.3.2 celery[redis]<6.0.0,>=5.2.7 certifi<2024.0.0,>=2023.7.22 cloudpickle==2.1.0 codecov<3.0.0,>=2.1 connexion[swagger-ui]<3.0.0,>=2.14 country-converter<2.0.0,>=1.0.0 coverage<7.0.0,>=6.4.1 cryptography<42.0.0,>=41.0.0 databricks-cli<0.18.0,>=0.17.7 databricks-sql-connector<3.0.0,>=2.0.5 datadog<0.46.0,>=0.45.0 ddtrace<1.13.0,>=1.12.0 ddtrace<2.0.0,>=1.2.1 decorator<6.0.0,>=5.1.1 docker<7.0.0,>=6.0.1 editdistance<0.7.0,>=0.6.2 faker<23.0.0,>=22.5.1 flask-compress<2.0.0,>=1.12 flask-cors<4.0.0,>=3.0 flask==2.2.5 flask_testing<0.9.0,>=0.8 flower<2.0.0,>=1.2.0 freezegun<2.0.0,>=1.2.1 gunicorn<21.0.0,>=20.1 hvac<0.11.0,>=0.10 inflect<7.0.0,>=6.0.4 inflect>=6.0.0 isort<6.0.0,>=5.11.4 isort<6.0.0,>=5.12.0 jsonschema<4.0.0,>=3.2 langchain<0.0.337,>=0.0.336 markdown<4.0.0,>=3.3 markupsafe<3.0.0,>=2.0 mergedeep<2.0.0,>=1.3.4 mlflow moto[s3,sqs]<4.0.0,>=3.0 mypy-boto3-quicksight<2.0.0,>=1.28.16 mypy-boto3-s3<2.0.0,>=1.26.58 mypy<2.0.0,>=1.1.1 networkx<4.0.0,>=3 nltk<4.0.0,>=3.8.1 nose-htmloutput<0.7.0,>=0.6 nose<2.0.0,>=1.3 numpy<2.0.0,>=1.23.2 openai<1.9.0,>=1.8.0 opensearch-py<3.0.0,>=2.3.2 opensearch-py[async]<3.0.0,>=2.4.2 orjson<4.0.0,>=3.8.5 pandas-stubs<3.0.0,>=2.1.4.231227 pandas==1.5.3 pgvector<0.3.0,>=0.2.1 pluggy<2.0.0,>=1.0 pre-commit<3.7.0,>=3.6 prometheus-client<0.14.0,>=0.13 protobuf>=3.20.3 psycopg-binary<4.0.0,>=3 psycopg2-binary<3.0.0,>=2.9.3 py-healthcheck<2.0.0,>=1.10 py-healthcheck<2.0.0,>=1.10.1 py<2.0.0,>=1.10 pyarrow>=8.0.0 pydantic<2.0.0,>=1.10.4 pydantic<2.0.0,>=1.9.2 pyhive<0.7.0,>=0.6.5 pyjwt==2.5.0 pylint<3.0.0,>=2.15.10 pylint<3.0.0,>=2.16.2 pylint<3.0.0,>=2.5 pyspark<3.4.0,>=3.3 pytest-alembic<1.0.0,>=0 pytest-asyncio<0.24.0,>=0.23.5 pytest-cov<4.0.0,>=3 pytest-mock<4.0.0,>=3.12.0 pytest-rerunfailures<11.0.0,>=10.2 pytest<8.0.0,>=7.2.1 python-arango<8.0.0,>=7.1 python-arango<8.0.0,>=7.5.1 python-jose[cryptography]<4.0.0,>=3.3.0 python-json-logger<3.0.0,>=2.0.4 python_dateutil<3.0.0,>=2.6 randomize<0.15.0,>=0.14 redis[hiredis]<4.7.0,>=4.6 requests-mock<2.0.0,>=1.8 requests<3.0.0,>=2 requests<3.0.0,>=2.28.1 requests<3.0.0,>=2.31.0 rich<13.0.0,>=12.6.0 ruff<0.2.0,>=0.1.8 safety<3.0.0,>=2.2 scikit-learn==1.1.1 setuptools six<2.0.0,>=1.16 streamlit<1.13.0,>=1.12.0 swagger-ui-bundle<0.0.10,>=0.0.9 testcontainers-opensearch<0.0.2,>=0.0.1rc1 testcontainers<4.0.0,>=3.5 testresources==2.0 thrift<0.17.0,>=0.16.0 tox-current-env<0.0.12,>=0.0.11 tox<5.0.0,>=4.4.5 tqdm<5.0.0,>=4.64.1 twine<5.0.0,>=4.0.2 types-bleach<7.0.0,>=6.0.0.3 types-cachetools<6.0.0,>=5.3.0.7 types-chardet<6.0.0,>=5.0.4.3 types-markdown<4.0.0,>=3.4.2.7 types-python-dateutil==2.8.14 types-pytz<2023.0.0,>=2022.5.0.0 types-redis<5.0.0,>=4.6.0.5 types-requests<3.0.0,>=2.30.0.0 types-setuptools<68.0.0,>=67.6.0.8 types-six<2.0.0,>=1.16.21 typing-extensions==4.2.0 ujson<6.0.0,>=5.7.0 unidecode<2.0.0,>=1.3.6 urllib3<2.0.0,>=1.26.9 waitress<3.0.0,>=2.1.2 werkzeug==2.2.3 wheel xgboost==1.4.0 --retries 5 --timeout 15 exited with 1 and STDERR:
ERROR: Cannot install black<23.13.0 and >=23.12 and black[jupyter]==23.12.1 because these package versions have conflicting dependencies.
ERROR: ResolutionImpossible: for help visit <https://pip.pypa.io/en/latest/topics/dependency-resolution/#dealing-with-dependency-conflicts>

 The conflict is caused by:
     The user requested black<23.13.0 and >=23.12
     black[jupyter] 23.12.1 depends on black 23.12.1 (requires-python:>=3.8))

 To fix this you could try to:
 1. loosen the range of package versions you've specified
 2. remove package versions to allow pip attempt to solve the dependency conflict

Have specified black multiple times for same resolve?

@refined-addition-53644 it's only because I'm in the process of adopting pants so I have multiple pyproject.toml files. I agree that I should ultimately remove that.

That might be throwing off pants.

I ended up finding the culprit. There were rogue requirements.txt buried super deep in the directory structure. After removing those from BUILD files it worked.