C++ component build failure: file_ops_component not copying source files

[avrabe]

Problem

C++ components fail to build with clang error:

clang: error: no such file or directory: 'bazel-out/.../calculator_c_component_cppwork/calculator_c.c'
clang: error: no input files

Root Cause

The cpp_component rule uses setup_cpp_workspace_action() which calls the file operations component to copy source files to a _cppwork directory. However, the file operations component is not successfully copying the source files to the expected location.

Build Process Flow

1. cpp_component rule processes //examples/cpp_component/calculator:calculator_c_component
2. Calls setup_cpp_workspace_action() to prepare workspace
3. Should copy src/calculator_c.c to calculator_c_component_cppwork/calculator_c.c
4. File copy fails or doesn't happen
5. clang tries to compile missing source file and fails

Evidence

• Source file exists: examples/cpp_component/calculator/src/calculator_c.c ✅
• BUILD file correctly references source: srcs = ["src/calculator_c.c"] ✅
• Expected location missing: calculator_c_component_cppwork/calculator_c.c ❌

Impact

• All C++ component builds fail
• Blocks CI with exclusions like -//examples/cpp_component/...
• Affects C++ test targets that depend on C++ components

Files Involved

• cpp/defs.bzl - cpp_component rule implementation
• tools/bazel_helpers/file_ops_actions.bzl - setup_cpp_workspace_action()
• tools/file_operations_component/* - File operations WebAssembly component

Investigation Needed

1. Check if file_ops_component tool is working correctly
2. Verify setup_cpp_workspace_action() parameter passing
3. Test file operations component in isolation
4. Check if WebAssembly component execution is failing silently

Workaround

Temporarily exclude C++ components from CI with -//examples/cpp_component/... until root cause is fixed.