The value of the dependencies field is a list of addresses of other targets. If code in target A directly depends on code in target B (e.g., by importing a symbol from B) then A should declare a dependency on B. There is no need to declare indirect dependencies (that is, transitive dependencies of your direct dependencies).

I think it would be helpful to mention that there are two types of dependencies: 3rdparty and other monorepo target.

Good idea! Related, we’re working on a project to add “dependency inference”. For python, Pants will be able to read your source code import statements to automatically populate

dependencies

. You can explicitly add any others you’d like

If that is successful, then the only dependencies that would need to be declared are for non-code files (eg

*.yaml

etc).

Precisely! Or if you for some reason used importlib.import, for example. Our goal is to reduce the maintenance burden of BUILD files, which we think is one of the sore spots of build tools like Pants and Bazel.

There are a number of parallels in

setup.py

(from setuptools) to the pant's

BUILD

files. Both define the following metadata: •

name

•

packages

or

source

code •

package_data

or

resources

•

install_requires

or

dependencies

(what you are proposing to automate) •

python_requires

or

compatibility

Interesting, I’ve never thought of comparing a

setup.py

to a BUILD file. At a high level, it’s a fair comparison. They both exist for metadata about some of your code.

field is to imitate the find_packages but with a find_dependencies method

Are you envisioning the user explicitly typing

find_dependencies

? Instead, the plan is that Pants will automatically do it no matter what (if you have the backend registered). If you explicitly specified everything, Pants will have nothing to add. If you explicitly specified 3/5 imports, then Pants will fill in the rest, etc

setup.py

requires people to type it explicitly. After thinking about it, it doesn't make sense for

BUILD

to require that. BUT it would be good to be able to turn the automatic find dependency off Just in Case™.

Agreed with being able to disable it. It’s especially helpful for debugging for users to be able to try a run with and without it Btw, the way you’ll see what Pants resolves is using the dependencies goal:

./pants dependencies project/app.py

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