is it possible to add a new option for an existing Pants goal using the plugin API? E.g.

./pants dependencies --my-flag

. The docs show how to add an option for a new subsystem, but I wonder if one can hook up into an existing goal?

What's the context?

yes, exactly, sorry if that was unclear.

./pants dependencies

would show all dependencies, but I am looking into adding an option defined in my in-repo plugin to avoid doing

./pants dependencies | xargs command ... | xargs command

. Using

cli.alias

won't work as it involves chaining multiple commands. I'd like instead to do this in Python before emitting output from the very first command.

not sure how you would an option to an existing subsystem. I first have a question about how does your plugin even change the semantics/code of a core goal?

I'd like to filter the output produced by the

dependencies

goal, so the option wouldn't interfere with the semantics at all. Essentially the last step filtering before returning

I don't think the current rules allow you to override an existing goal in that manner.

so my only option then is to extend the Pants core 😉

or write a new goal (e.g.,

my-deps

) and then either copy/paste the impl of

dependencies

goal or call its impl (which now keeps its same type) but pass in a

Console

wrapper that does the filtering

https://www.pantsbuild.org/v2.7/docs/reference-dependencies#section-type I want to resurrect this one 😄

hmm any reason why it was deprecated?

from https://www.pantsbuild.org/v2.8/docs/reference-dependencies#section-type type --dependencies-type=<DependencyType> PANTS_DEPENDENCIES_TYPE one of: source, 3rdparty, source-and-3rdparty default: source Deprecated, will be removed in version: 2.9.0.dev0. This option is misleading and not very useful. In the future there will be a more robust way of querying and filtering dependencies. Meanwhile you can get the list of requirement strings for a set of targets using something like ./pants dependencies :: | xargs ./pants filter --target-type=python_requirement | xargs ./pants peek | jq -r '.[][&quot;requirements&quot;][]' https://github.com/pantsbuild/pants/pull/13431/files

or invent that more robust way :)

You CAN add an option to other goals' subsystems, but that's really only useful in your rules, which in this case wouldn't be considered