[Bug]: py_layer_tier ignores `root`

[tsudol-plaid]

What happened?

...or I don't understand what it's supposed to do.

Given a py_layer_tier like:

py_layer_tier(
  name = "my_tier",
  root = "/my_favorite_dir",
)

I expect it to put the files in /my_favorite_dir/my_app.runfiles, or perhaps /my_favorite_dir.runfiles. I'm not sure.

Instead, it puts the files in /app.runfiles.

I'm seeing this on a full image build. To save time, I've done the reproduction with py_image_layer + checking the output tars.

Version

Development (host) and target OS/architectures:
Tested on:
Linux x86-64 host and target
MacOS arm host and target

Output of bazel --version: bazel 9.2.0

Version of the Aspect rules, or other relevant rules from your
WORKSPACE or MODULE.bazel file: 2.0.0-alpha.6

Language(s) and/or frameworks involved: Python

How to reproduce

First, set up a repository containing:
MODULE.bazel:

module(
  name = "no-root",
  version = "0.1.0",
)

bazel_dep(name = "aspect_rules_py", version = "2.0.0-alpha.6")


BUILD.bazel:

load("@aspect_rules_py//py:defs.bzl", "py_binary", "py_image_layer", "py_layer_tier")

py_binary(
  name = "main",
  srcs = ["main.py"],
  deps = [],
)

py_layer_tier(
  name = "my_tier",
  root = "/my_favorite_dir",
)

py_image_layer(
  name = "image",
  binary = ":main",
  layer_tier = "//:my_tier",
)


main.py:

print("Hello, world!")


Build the image layers:

bazel build //:image  


Check the contents of the output tar:

tar -ztf bazel-bin/image_default.tar.gz | head


Expectation:
Something like `/my_favorite_dir/my_app.runfiles/_main/._main.venv/bin/python`

Actual result:
A list of files like:
`./app.runfiles/_main/._main.venv/bin/python`

Any other information?

No response