How can I put the path to the Python interpreter into a string?

[allsey87]

Given that I have the following content inside of my MODULE.bazel, how can I get the path to the specified Python interpreter?

bazel_dep(name = "rules_python", version = "0.31.0")
python = use_extension("@rules_python//python/extensions:python.bzl", "python")
python.toolchain(python_version = "3.11.3")
use_repo(python, python_3_11_3 = "python_3_11_3")

For example, inside of a configure_make rule such as:

configure_make(
    name = "mypackage",
    lib_source = "@mypackage//:all",
    configure_options = [
        "--with-python=path/to/python3.11", # as specified above
    ],
)

[allsey87]

This documentation suggests that the path to the interpreter can be accessed by setting the toolchain as follows and using the $(PYTHON3) make variable as follows:

genrule(
    name = "test_current_py_toolchain",
    srcs = [],
    outs = ["out.txt"],
    cmd = "$(PYTHON3) --version > $(location out.txt)",
    toolchains = ["//python:current_py_toolchain"],
)

However, this gives me the error that the package //python does not exist. Is was able to get the following working, although it would be nicer if this was working with the toolchain and the $(PYTHON3) make variable:

genrule(
    name = "test",
    cmd = "$$(realpath $(location @python_3_11_3//:python3)) --version > $(RULEDIR)/out.txt",
    tools = ["@python_3_11_3//:python3"],
    outs = ["out.txt"]
)

[allsey87]

One step closer: I am now using toolchain, but I am not getting the version of Python that I declared in my MODULE.bazel

genrule(
    name = "test",
    cmd = "$(PYTHON3) --version > $(RULEDIR)/out.txt",
    toolchains = ["@rules_python//python:current_py_toolchain"],
    outs = ["out.txt"]
)

Querying the repository declared in MODULE.bazel seem to show it is set up and working correctly, however, there is no toolchain target.

$ bazel query @python_3_11_3//:*
@python_3_11_3//:BUILD.bazel
@python_3_11_3//:aarch64-apple-darwin
@python_3_11_3//:aarch64-unknown-linux-gnu
@python_3_11_3//:defs.bzl
@python_3_11_3//:files
@python_3_11_3//:includes
@python_3_11_3//:libpython
@python_3_11_3//:pip
@python_3_11_3//:ppc64le-unknown-linux-gnu
@python_3_11_3//:py3_runtime
@python_3_11_3//:python3
@python_3_11_3//:python_headers
@python_3_11_3//:python_runtimes
@python_3_11_3//:s390x-unknown-linux-gnu
@python_3_11_3//:x86_64-apple-darwin
@python_3_11_3//:x86_64-pc-windows-msvc
@python_3_11_3//:x86_64-unknown-linux-gnu

[allsey87]

@aignas any hints?