fix(ci): use C++ compiler for Docker builds (#2304)

Author: abetlen

CMakeLists.txt

@@ -179,7 +179,7 @@ if (LLAMA_BUILD)
         # The Python package only ships mtmd as a shared library.
         # Upstream mtmd also defines CLI compatibility wrappers, but those are
         # not installed here and can fail to link in minimal Docker toolchains.
-        foreach(target llama-llava-cli llama-gemma3-cli llama-minicpmv-cli llama-qwen2vl-cli llama-mtmd-debug)
+        foreach(target llama-llava-cli llama-gemma3-cli llama-minicpmv-cli llama-qwen2vl-cli llama-mtmd-cli llama-mtmd-debug)
             if (TARGET ${target})
                 set_target_properties(${target} PROPERTIES EXCLUDE_FROM_ALL TRUE)
             endif()

docker/simple/Dockerfile

@@ -27,7 +27,7 @@ RUN python3 -m pip install --upgrade pip
 
 RUN python3 -m pip install --upgrade pip pytest cmake scikit-build setuptools fastapi uvicorn sse-starlette pydantic-settings starlette-context
 
-RUN CMAKE_ARGS="${CMAKE_ARGS}" pip install . --verbose
+RUN CC=gcc CXX=g++ CMAKE_ARGS="${CMAKE_ARGS}" pip install . --verbose
 
 # Set environment variable for the host
 ENV HOST=0.0.0.0