Hi, I am trying to evaluate

pants

for a mono repo in my project. The repository still does not have a build system yet. The requirement for me is to migrate existing libraries which are packaged using

setuptools

and

setuptools-scm

with

pyproject.toml

. I followed the documentation and created the

BUILD

file for the project. However,

pants

is not able to create a package from the source code. Below is the error that I get:

config = read_configuration(filepath, True, ignore_option_errors, dist)
usage: backend_shim.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
   or: backend_shim.py --help [cmd1 cmd2 ...]
   or: backend_shim.py --help-commands
   or: backend_shim.py cmd --help

error: invalid command 'bdist_wheel'

Can anyone help me resolve this issue?

Did you create one

BUILD

file, or all

BUILD

files?

My folder structure is like this

.
├── my-lib
│   ├── BUILD
│   ├── lib
│   │   ├── __init__.py
│   │   └── main.py
│   └── pyproject.toml
└── pants.toml

The contents of

BUILD

is as shown below:

resource(name="pyproject", source="pyproject.toml")

python_distribution(
    name="my-lib",
    dependencies=[
        ":pyproject",
        # Dependencies on code to be packaged into the distribution.
    ],
    provides=python_artifact(
        name="my-lib",
    ),
    # Example of setuptools config, other build backends may have other config.
    wheel_config_settings={"--build-option": ["--python-tag", "py310.py311"]},
)

pants

requires a build in every folder. Call

pants tailor ::

this should create the missing

BUILD

file and add some required targets. Regarding the

python_distribution

target I think you should change your

weel_config_settings

to

wheel_config_settings={"--global-option": ["--python-tag", "py39"]}.

Further, try to set

generate_setup=True

if you want pants to infer information from your

pyproject.toml

.

Small adjustment, Pants doesn’t “require” a build file in every folder. I use recursive globs in my single BUILD file per monorepo service/project

Yes not require. But I would say it is somewhat of a best practice.

It is my ultimate goal to get rid of that requirement...

I ran

pants tailor ::

and adapted the BUILD file as mentioned above. It still gives an error that the lib package doesnt exist.

@happy-kitchen-89482 That would be nice, but since

tailor

does most of the work for the developer it is not to big of a pain, for me at least. Further, compared to bazel it is not even in the same league. In its current state, would you suggest using one

BUILD

file per directory, or as @wide-midnight-78598 does it one per service/project leveraging recursive globs?

@lemon-yak-80782 I added

:lib

in

python_distribution

as a dependency, and it worked. Thanks. @wide-midnight-78598 How to use recursive globs without creating multiple BUILD files?

@gentle-florist-96289 You can define

source

in the

python_sources

target. For example:

foo/**/*.py

.

@lemon-yak-80782 This doesn't seem to work properly. if I give sources as

["lib/**/*.py"]

and if I have nested directories inside lib, it doesn't copy them correctly in the

chroot

directory in the temp. I get the contents of the lib folder in the chroot at the same level as

pyproject.toml

and it doesn't copy the inner directories.

Take a look here, https://www.pantsbuild.org/docs/validating-dependencies#anchoring-mode-for-path-globs. I think anchoring the glob (

//

or

/

) should help.

Okay I seem to be getting a hang of the project setup. Glob is working now. However, can you tell me how to include the data files from the lib as well? Currently the

python_sources

only accepts

*.py

files. I have some

json

and

sqlite3

files that do not get packaged. I believe these files should be created as a separate source and add as a dependency in the

python_distribution

. Can you please help with this?

Yes, there is a resource target.

The one BUILD file per directory (as implemented by tailor) is useful when you need to start overriding settings for specific packages. You can do that in higher-level build file (with the

overrides={...}

field) but it's a bit more clunky if you have many of them.