Ambient dependencies?

[njlr]

I was wondering if there is a way to express this in rules_py?

Pacakge foo expects requires package bar (virtually):

py_library(
  name = "foo",
  virtual_deps = [
    "bar",
  ],
)

Then an app explicitly does not provide bar, because it is expecte to be pre-installed on the deployment target host (such as Docker image):

py_binary(
  name = "app",
  deps = [
    ":foo",
  ],
  ambient_deps = [
    "bar",
  ],
)

Is such a thing possible?

[njlr]

Perhaps using a dummy target?

py_library(
  name = "foo",
  virtual_deps = [
    "bar",
  ],
)

py_library(
  name = "dummy",
  srcs = [],
)

py_binary(
  name = "app",
  srcs = [
    "main.py",
  ],
  main = "main.py",
  deps = [
    ":foo",
  ],
  resolutions = resolutions.empty().override({
    "bar": ":dummy",
  }),
)