[C++][CI] macOS compile errors due to boost::asio #45053
Description
Describe the bug, including details regarding any error messages, version, and platform.
See example at https://github.com/apache/arrow/actions/runs/12378188460/job/34549488301?pr=45042#step:12:1551
FAILED: src/arrow/CMakeFiles/arrow_testing_objlib.dir/testing/process.cc.o
/opt/homebrew/bin/ccache /Applications/Xcode_15.4.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ -DARROW_HAVE_NEON -DARROW_TESTING_EXPORTING -DBOOST_ATOMIC_DYN_LINK -DBOOST_ATOMIC_NO_LIB -DBOOST_CONTEXT_DYN_LINK -DBOOST_CONTEXT_NO_LIB -DBOOST_DATE_TIME_DYN_LINK -DBOOST_DATE_TIME_NO_LIB -DBOOST_FILESYSTEM_DYN_LINK -DBOOST_FILESYSTEM_NO_LIB -DBOOST_PROCESS_DYN_LINK -DBOOST_PROCESS_HAVE_V1 -DBOOST_PROCESS_HAVE_V2 -DBOOST_PROCESS_NO_LIB -DBOOST_SYSTEM_DYN_LINK -DBOOST_SYSTEM_NO_LIB -I/Users/runner/work/arrow/arrow/build/cpp/src -I/Users/runner/work/arrow/arrow/cpp/src -I/Users/runner/work/arrow/arrow/cpp/src/generated -isystem /Users/runner/work/arrow/arrow/build/cpp/_deps/googletest-src/googletest/include -isystem /Users/runner/work/arrow/arrow/build/cpp/_deps/googletest-src/googletest -isystem /Users/runner/work/arrow/arrow/build/cpp/_deps/googletest-src/googlemock/include -isystem /Users/runner/work/arrow/arrow/build/cpp/_deps/googletest-src/googlemock -isystem /Users/runner/work/arrow/arrow/cpp/thirdparty/flatbuffers/include -isystem /opt/homebrew/Cellar/rapidjson/1.1.0/include -isystem /opt/homebrew/include -fno-aligned-new -Qunused-arguments -fcolor-diagnostics -Wall -Wextra -Wdocumentation -DARROW_WARN_DOCUMENTATION -Wshorten-64-to-32 -Wno-missing-braces -Wno-unused-parameter -Wno-constant-logical-operand -Wno-return-stack-address -Wdate-time -Wno-unknown-warning-option -Wno-pass-failed -march=armv8-a -g -Werror -O0 -ggdb -g1 -std=c++17 -arch arm64 -isysroot /Applications/Xcode_15.4.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX14.5.sdk -fPIC -MD -MT src/arrow/CMakeFiles/arrow_testing_objlib.dir/testing/process.cc.o -MF src/arrow/CMakeFiles/arrow_testing_objlib.dir/testing/process.cc.o.d -o src/arrow/CMakeFiles/arrow_testing_objlib.dir/testing/process.cc.o -c /Users/runner/work/arrow/arrow/cpp/src/arrow/testing/process.cc
/Users/runner/work/arrow/arrow/cpp/src/arrow/testing/process.cc:88:18: error: expected namespace name
namespace asio = BOOST_PROCESS_V2_ASIO_NAMESPACE;
^
/Users/runner/work/arrow/arrow/cpp/src/arrow/testing/process.cc:246:3: error: use of undeclared identifier 'asio'; did you mean 'boost::asio'?
asio::io_context ctx_;
^~~~
boost::asio
/opt/homebrew/include/boost/asio/writable_pipe.hpp:26:11: note: 'boost::asio' declared here
namespace asio {
^
2 errors generated.
Component(s)
C++, Continuous Integration