Examples please.

[mmes]

This repo is nearly always the first hit when searching for bazel + pybind11. New to PyBind11, I am having a lot of trouble building a python module, then importing it into an embedded interpreter. All related searches are cmake oriented.

It would be great if the rules this bzlmod defined would be documented with examples.

[junyer]

Sorry, but just to confirm, are you looking for pybind11_bazel usage examples? Or are you actually looking for pybind11 usage examples?

[tenspd137]

I have the same issue. I have a very simple example I am trying to run. I keep getting the following error with bazel build /... :

ERROR: /home/dayd/.cache/bazel/_bazel_dayd/c693b355f9fcfefcc68f8a5aae9bbdac/external/rules_python/python/cc/BUILD.bazel:15:22: While resolving toolchains for target @@rules_python//python/cc:current_py_cc_headers (312a038): No matching toolchains found for types @@rules_python//python/cc:toolchain_type.
To debug, rerun with --toolchain_resolution_debug='@@rules_python//python/cc:toolchain_type'
If platforms or toolchains are a new concept for you, we'd encourage reading https://bazel.build/concepts/platforms-intro.

My workspace file is pretty simple:

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

VERSION="0.32.2"

http_archive(
    name = "rules_python",
    #sha256 = SHA,
    strip_prefix = "rules_python-{}".format(VERSION),
    url = "https://github.com/bazelbuild/rules_python/releases/download/{}/rules_python-{}.tar.gz".format(VERSION,VERSION),
)

load("@rules_python//python:repositories.bzl", "py_repositories")

py_repositories()

load("@rules_python//python:repositories.bzl", "python_register_toolchains")

python_register_toolchains(
    name = "python_3_11",
    # Available versions are listed in @rules_python//python:versions.bzl.
    # We recommend using the same version your team is already standardized on.
    python_version = "3.11.8",
)

load("@python_3_11//:defs.bzl", "interpreter")


http_archive(
  name = "pybind11_bazel",
  strip_prefix = "pybind11_bazel-2.12.0",
  urls = ["https://github.com/pybind/pybind11_bazel/archive/v2.12.0.zip"],
)
# We still require the pybind library.
http_archive(
  name = "pybind11",
  build_file = "@pybind11_bazel//:pybind11-BUILD.bazel",
  strip_prefix = "pybind11-2.12.0",
  urls = ["https://github.com/pybind/pybind11/archive/v2.12.0.zip"],
)

and my BUILD file:

load("@pybind11_bazel//:build_defs.bzl", "pybind_extension")
load("@rules_python//python:defs.bzl", "py_binary")

py_binary(
  name = "main",
  srcs = ["main.py"],
)
pybind_extension(
    name = "my_pb_mod_ext", 
    srcs = ["my_pb_mod.cc"],
)

py_library(
    name = "my_pb_mod",
    data = [":my_pb_mod_ext.so"],
)

The py_binary there was just to see if I was using the rules_python stuff right.

[tenspd137]

Update - It seems that if I follow instructions fro 2.11.1 - seems to work. 2.12.0 - does not.

[junyer]

Quoting https://github.com/pybind/pybind11_bazel/issues/78#issuecomment-1992350163:

It's probably impossible to use rules_python from a WORKSPACE file with Bzlmod enabled. I suggest adopting Bzlmod at least partially: populate a MODULE.bazel file to the extent possible; and then keep everything else in a WORKSPACE.bzlmod file.

[junyer]

@roceb has very kindly contributed a basic example as per commit d85a646a002f1008e6c2429ba350e577d45ed61a. Is there anything else that folks would like to see?

[hofbi]

I think the basic example is already very helpful and could be enough to close https://github.com/pybind/pybind11_bazel/issues/19, https://github.com/pybind/pybind11_bazel/issues/40, and this issue.

[junyer]

SGTM. Thanks!