Fix C++ compiler detection failure during CMake project phase when building RPM on macOS

Environment

• Repository: git@gitlab.oceanbase-dev.com:oceanbase-ce-publish/seekdb.git
• Branch: master
• Machine: macOS
• Working Directory: /Users/admin/lvw/seekdb_mac

Description

When compiling the master branch on macOS, the build.sh rpm --init command fails during the CMake project phase because it cannot detect a valid C++ compiler.

Steps to Reproduce

1. Clone the repository:

   git clone -b master --depth=20 git@gitlab.oceanbase-dev.com:oceanbase-ce-publish/seekdb.git seekdb
   

2. Run the build script for release:

   bash build.sh release --init
   

3. Navigate to the build directory and compile:

   cd build_release
   make -j 7 seekdb
   cd ..
   

4. Attempt to build the tarball and RPM package:

   bash build.sh tgz --init --make -j32
   bash build.sh rpm --init --make -j32
   

The bash build.sh rpm --init --make -j32 command fails with an error indicating CMake cannot find a suitable C++ compiler.

Impact

This blocks the creation of RPM packages from the master branch on macOS development environments.

Proposed Solution

Investigate and fix the CMake configuration or the build.sh script to correctly locate and use the C++ compiler (e.g., clang++) on macOS systems during the RPM build phase.

Start with build.sh and the CMake project phase used by bash build.sh rpm --init --make -j32 on macOS. Reproduce the failure, then trace how the RPM build selects the C++ compiler and compare it with the release build's compiler configuration. Done means the RPM build detects a valid macOS compiler such as clang++ and completes successfully.