Python 3.15, MacOS build error

[slott56]

This is an install on an Apple M4 chip (ARM), macOS 26.5.1 (25F80).

Using Python 3.15.0a6 environment at: .tox/py315
Resolved 90 packages in 2.15s
  × Failed to build `google-re2==1.1.20251105`
  ├─▶ The build backend returned an error
  ╰─▶ Call to `setuptools.build_meta:__legacy__.build_wheel` failed (exit status: 1)

      [stdout]
      running bdist_wheel
      running build
      running build_py
      creating build/lib.macosx-11.0-arm64-cpython-315/re2
      copying re2/__init__.py -> build/lib.macosx-11.0-arm64-cpython-315/re2
      running build_ext
      building '_re2' extension
      creating build/temp.macosx-11.0-arm64-cpython-315
      c++ -fno-strict-overflow -Wsign-compare -Wunreachable-code -DNDEBUG -g -O3 -Wall -O3 -arch arm64 -mmacosx-version-min=11.0 -Wno-nullability-completeness -Wno-expansion-to-defined -Wno-undef-prefix -fPIC
      -I/Users/slott/.cache/uv/builds-v0/.tmpxrcAhw/include -I/Users/slott/.local/share/uv/python/cpython-3.15.0a6-macos-aarch64-none/include/python3.15 -c _re2.cc -o build/temp.macosx-11.0-arm64-cpython-315/_re2.o -fvisibility=hidden

      [stderr]
      /Users/slott/.cache/uv/builds-v0/.tmpxrcAhw/lib/python3.15/site-packages/setuptools/dist.py:765: SetuptoolsDeprecationWarning: License classifiers are deprecated.
      !!

              ********************************************************************************
              Please consider removing the following classifiers in favor of a SPDX license expression:

              License :: OSI Approved :: BSD License

              See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
              ********************************************************************************

      !!
        self._finalize_license_expression()
      _re2.cc:15:10: fatal error: 'absl/strings/string_view.h' file not found
         15 | #include "absl/strings/string_view.h"
            |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
      1 error generated.
      error: command '/usr/bin/c++' failed with exit code 1

      hint: This usually indicates a problem with the package or the build environment.

The needed includes are in /opt/local/include/

ls -l /opt/local/include/absl/strings/string_view.h 
-rw-r--r--@ 1 root  admin  29629 Aug  1  2024 /opt/local/include/absl/strings/string_view.h

[MajorTanya]

Did you check the Readme's build instructions?

Building RE2 requires a C++17 compiler and the Abseil library.
Building the tests and benchmarks requires
GoogleTest
and Benchmark.
To obtain those:

• Linux: apt install libabsl-dev libgtest-dev libbenchmark-dev
• macOS: brew install abseil googletest google-benchmark pkg-config-wrapper
• Windows: vcpkg install abseil gtest benchmark
  or vcpkg add port abseil gtest benchmark

I have no idea about C++ or building re2, but the error looks like you don't have abseil available to me?

[slott56]

I wasn't expecting to have to build it, since it's published to the Python Package Index.

Your summary is wonderfully helpful! I think I can justify adding these instructions to the project I support so we can test with Python 3.15 until the package on PyPI is more complete.

[MajorTanya]

I wasn't expecting to have to build it, since it's published to the Python Package Index.

Your summary is wonderfully helpful! I think I can justify adding these instructions to the project I support so we can test with Python 3.15 until the package on PyPI is more complete.

it's probably because the maintainers hasn't published built wheels for the 3.15 betas yet