Update nanobind to v2.0

[hawkinsp]

nanobind v2.0 was released today; google/benchmark should upgrade.

A change something like the following should work:

--- a/third_party/benchmark/bindings/python/google_benchmark/benchmark.cc
+++ b/third_party/benchmark/bindings/python/google_benchmark/benchmark.cc
@@ -109,7 +109,7 @@ NB_MODULE(_benchmark, m) {
   using benchmark::Counter;
   nb::class_<Counter> py_counter(m, "Counter");

-  nb::enum_<Counter::Flags>(py_counter, "Flags")
+  nb::enum_<Counter::Flags>(py_counter, "Flags", nb::is_arithmetic())
       .value("kDefaults", Counter::Flags::kDefaults)
       .value("kIsRate", Counter::Flags::kIsRate)
       .value("kAvgThreads", Counter::Flags::kAvgThreads)
@@ -121,7 +121,7 @@ NB_MODULE(_benchmark, m) {
       .value("kAvgIterationsRate", Counter::Flags::kAvgIterationsRate)
       .value("kInvert", Counter::Flags::kInvert)
       .export_values()
-      .def(nb::self | nb::self);
+      .def("__or__", [](Counter::Flags a, Counter::Flags b) { return a | b; });

   nb::enum_<Counter::OneK>(py_counter, "OneK")
       .value("kIs1000", Counter::OneK::kIs1000)

although I don't have time right now to figure out the bazel build updates, etc.

[nicholasjng]

This will require a new release of nanobind-bazel on the BCR, since that's being used to generate the extension.

I haven't gotten around to implement stubgen yet to generate stubs during the Bazel build, but that should not very difficult (albeit I'm not a Bazel expert). I'll find some time to get it done soon.

EDIT: nvm, you already posted an issue. thanks!

[varshneydevansh]

I am trying to do this and did the version change in the MODULE.build file.

 base  devansh   1790_update_nanobind -  bazel build                               [24/05/24| 6:37PM]
Extracting Bazel installation...
Starting local Bazel server and connecting to it...
ERROR: Error computing the main repository mapping: in module dependency chain <root> -> [email protected]: module not found in registries: [email protected]
Computing main repo mapping: 
    Fetching https://bcr.bazel.build/modules/rules_python/0.31.0/MODULE.bazel
    Fetching https://bcr.bazel.build/modules/googletest/1.12.1/MODULE.bazel
    Fetching https://bcr.bazel.build/modules/platforms/0.0.7/MODULE.bazel
    Fetching https://bcr.bazel.build/modules/protobuf/3.19.6/MODULE.bazel
    Fetching https://bcr.bazel.build/modules/apple_support/1.5.0/MODULE.bazel
    Fetching https://bcr.bazel.build/modules/rules_java/7.4.0/MODULE.bazel
    Fetching https://bcr.bazel.build/modules/buildozer/6.4.0.2/MODULE.bazel
    Fetching https://bcr.bazel.build/modules/rules_foreign_cc/0.10.1/MODULE.bazel

Now I understood how it's dependent on the https://github.com/nicholasjng/nanobind-bazel

So, now I have to implement stubgen to generate stubs in the nanobind-bazel as told by @nicholasjng ?