Support remote constraints files

[manojkarthick]

Big fan of ruff and just checking out uv from the twitter announcement. Thanks a lot for creating this and improving the python ecosystem.

Looks like constraints using --constraint flag inside a requirements.txt file is not supported?

I'm receiving the following error:

❯ uv pip install -r requirements.txt
error: Error parsing included file in `requirements.txt` at position 0
  Caused by: failed to open file `/Users/manojkarthick/code/sandbox/uvtest/"https://raw.githubusercontent.com/apache/airflow/constraints-2.6.3/constraints-3.10.txt"`
  Caused by: No such file or directory (os error 2)

Requirements file with constraints that fails

``` --constraint "https://raw.githubusercontent.com/apache/airflow/constraints-2.6.3/constraints-3.10.txt" virtualenv==20.23.1 boto3==1.26.161 cachetools==5.3.1 pandas==1.5.3 numpy==1.24.4 pendulum==2.1.2 psycopg2-binary==2.9.6 protobuf==4.23.4 PyGithub==1.59.0 SQLAlchemy==1.4.49 apache-airflow-providers-amazon==8.2.0 apache-airflow-providers-http==4.4.2 apache-airflow-providers-common-sql==1.5.2 apache-airflow-providers-jdbc==4.0.0 apache-airflow-providers-postgres==5.5.1 apache-airflow-providers-docker==3.7.1 apache-airflow-providers-ssh==3.7.1 apache-airflow-providers-apache-spark==4.1.1 apache-airflow-providers-snowflake==4.2.0 apache-airflow-providers-slack==7.3.1 apache-airflow-providers-elasticsearch==4.5.1 apache-airflow-providers-databricks==4.3.0 apache-airflow-providers-github==2.3.1 snowflake-connector-python==3.0.4 snowflake-sqlalchemy==1.4.7 protobuf==4.23.4 fsspec==2023.6.0 attrs==23.1.0 requests==2.31.0 uszipcode==1.0.1 clickhouse-connect==0.7.0 ```

I do see https://github.com/astral-sh/uv/issues/172, so please feel free to close this issue if it's redundant.

[zanieb]

Hi! Thanks for the kind words.

It looks like we support this during pip compile but not pip install which seems like an oversight.

[charliermarsh]

Could the issue here be that it's a remote URL? I'm not sure we support that yet.

[zanieb]

Yeah actually that does look like the case, adding test coverage for pip install with constraints right now...

[recrsn]

Looks like we don't have support for remote constraint URLs yet, not even on the --constraint flag

[zanieb]

Yeah this is the problem not the presence of --constraint (https://github.com/astral-sh/uv/pull/1334)

[jannisko]

So I guess this could be solved by replacing the PathBuf here https://github.com/astral-sh/uv/blob/8675f66e74dc2c7d45b65e9aef21479c97dd0015/crates/uv/src/main.rs#L174 with something like a DynObjectStore: https://docs.rs/object_store/latest/object_store/#configuration-system to automatically dispatch to a local file or url depending on what is given. I'd be down to implement this if you think the additional dependency is worth it. If you know another crate that could help us do this let me know. 🙂

[jensens]

I think my problem is related:

(venv) ~/ws/sandbox/cplone$ uv pip install -r requirements.txt 
error: Error parsing included file in `requirements.txt` at position 0
  Caused by: failed to open file `https://dist.plone.org/release/6.0.9/constraints.txt`
  Caused by: No such file or directory (os error 2)
(venv) ~/ws/sandbox/cplone$ uv --version
uv 0.1.10

requirements.txt:

-c https://dist.plone.org/release/6.0.9/constraints.txt
waitress_fastlisten
Plone

That said, this is an essential feature of pip to get remote constraints.