Take https://github.com/pantsbuild/example-python. There are three sources of dependencies that are shown: 1. The dependency inference (

helloworld/translator/translator.py:lib

due to

from helloworld.translator.translator import LanguageTranslator

) 2. The manually set dependencies (the JSON file is being read, so

dependencies=[":translations"],

had to be set) 3. Anything from the

overrides

field, if set. Currently there is none.

$ pants dependencies helloworld/greet/greeting.py

//:reqs#setuptools
//:reqs#types-setuptools
helloworld/greet:translations
helloworld/translator/translator.py:lib

Now, if I want just one file out of many that may be owned by a build target to depend on something extra (e.g. all files depend on a JSON file and just one file depends on a YAML file), one would intuitively want to do:

python_sources(
    name="lib",
    dependencies=[":translations"],
    overrides={"greeting.py": {"dependencies": ["helloworld/main.py:lib"]}}
)

In this example picking

main.py

to keep it simple. The

main.py

does appear, however, the

helloworld/greet:translations

is gone because the

overrides

completely replaced the value of the

dependencies

field of that target.

$ pants dependencies helloworld/greet/greeting.py

//:reqs#setuptools
//:reqs#types-setuptools
helloworld/main.py:lib
helloworld/translator/translator.py:lib

While we don't have an

extends

field that would let to extend the dependencies (of course this would be applicable only to some fields -- it doesn't make sense to extend the timeout for instance), I don't think we have a way to make sure that only some of the files under a target generator get some extra dependencies without duplicating "common" dependencies that all files share?

to get the dependency set manually on the JSON file back, it needs to be set in two places -- once in

dependencies

and once in `overrides`:

python_sources(
    name="lib",
    dependencies=[":translations"],
    overrides={"greeting.py": {"dependencies": [":translations", "helloworld/main.py:lib"]}}
)

if the dependencies list is long, it may help to extract them into a variable like this:

common_deps = [":translations"]
python_sources(
    name="lib",
    dependencies=common_deps,
    overrides={"greeting.py": {"dependencies": common_deps + ["helloworld/main.py:lib"]}}
)

which is not terrible, but not great either