I'm implementing a plugin to show the path from X to Y. X depends on Y transitively, so I want to show the middle dependencies from X to Y (e.g. X -> X1 -> X2 -> Y). I've implemented a recursive search, but when I run it I get:

Exception: Get(Targets, DependenciesRequest, DependenciesRequest(field=<class 'pants.engine.target.Dependencies'>(alias='dependencies', address=//path/to/file.py:../../../asdf, value=None, default=None), include_special_cased_deps=False)) was not detected in your @rule body at rule compile time. Was the `Get` constructor called in a separate function, or perhaps dynamically? If so, it must be inlined into the @rule body.

Does this mean that I cannot have a recursive function that calls Get?

Hi! It sounds like you’re trying to implement the

paths

goal: https://www.pantsbuild.org/docs/reference-paths

Hi Andreas, I wasn't aware this already existed, it works as expected, thanks!

When was

paths

added? That's cool

https://github.com/pantsbuild/pants/pull/13778 ;)

I think we didn't publcizie

paths

enough, actually! It's not in release blogs. Looks like 2.9

As for a .dot file, you can get the data you need in JSON form using

./pants peek

but you'll have to transform it to dot format

what's a recommended way to do that? What comes to mind for me is to grab

networkx

as a plugin requiremnt and use it to run graph algorithms

I think right now people are doing this outside of Pants. I have advocated for a

./pants graph

goal, but not everyone agrees it should exist.

well, it's very general, so I think it would be hard to come up with what a

graph

goal would do that would meet people's needs

I instead am +1 for our docs having more pre-baked recipes

I'm also reminded that https://github.com/vasturiano/force-graph might be useful for visualizing this (thanks @bitter-ability-32190), and

./pants paths

should work nicely with that, since it doesn't seem to return cycles (according to https://github.com/pantsbuild/pants/blob/main/src/python/pants/backend/project_info/paths.py)

I don't think

paths

on its own returns enough information for a graph, as you have to provide --from and --to?

peek

is probably what you want

Yeah I think I used

peek

for my PoC

it provides enough info for a subgraph, which is what I want really

In the end I've used graphviz (https://github.com/xflr6/graphviz) to create the graph, by converting the output from

pants paths

to graphviz edges.