[LTS] Integration test failed from `module_xc` unit tests failing to link due to missing ModuleBase::TITLE dependency

[QuantumMisaka]

Describe the Testing Issue

Summary

On the LTS branch, the Integration Test and Unit Test / Test (pull_request) workflow can fail during the build step when BUILD_TESTING=ON is enabled. The failure happens before the test step is executed.

Failure

Affected targets include:

• XCTest_HSE
• XCTest_PBE
• XCTest_PZ_SPN
• XCTest_SCAN

Representative linker error:

/usr/bin/ld: CMakeFiles/XCTest_HSE.dir/__/xc_functional.cpp.o:
undefined reference to `ModuleBase::TITLE(std::string const&, std::string const&, bool)'
collect2: error: ld returned 1 exit status

Root Cause

source/module_hamilt_general/module_xc/xc_functional.cpp calls ModuleBase::TITLE(...)

The implementation of ModuleBase::TITLE is provided by: source/module_base/tool_title.cpp

The main ABACUS executable links the base object library, which includes tool_title.cpp, so the main program builds successfully.

However, several module_xc unit test targets in: source/module_hamilt_general/module_xc/test/CMakeLists.txt compile ../xc_functional.cpp directly into standalone test executables without also linking or compiling the implementation that provides ModuleBase::TITLE. As a result, those test executables fail at link time.

Expected Behavior

All module_xc unit test executables should link successfully when BUILD_TESTING=ON.

Additional Context

This problem is raised from #7321, However the failure of Integration Test and Unit Test / Test (pull_request) seems to have no relation with toolchain update, which should be fixed seperately from Toolchain PR.

Task list for Issue attackers (only for developers)

• Understand the testing issue described by the developer.
• Review the specific test case, expected and actual results, and any error messages.
• Identify the root cause of the test failure or issue.
• If a possible solution is suggested, evaluate its feasibility and effectiveness.
• Implement a fix for the test failure or issue, or create a new test case if needed.
• Verify that the fix resolves the testing issue and the test case passes.
• Review and update any relevant documentation, such as test plans or user guides.
• Ensure the testing issue is resolved and close the ticket.
• Share any lessons learned or best practices with the team to prevent similar issues in the future.

[QuantumMisaka]

@dyzheng @PeizeLin Have a look, thanks !

[Growl1234]

It seems this issue was brought by #6714.