try fix protobuf on cmake

Author: mudler

.github/workflows/test.yml

@@ -68,7 +68,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install build-essential ffmpeg
           
-          sudo apt-get install -y ca-certificates cmake curl patch  libprotobuf-dev protobuf-compiler
+          sudo apt-get install -y ca-certificates cmake curl patch libabsl-dev libprotobuf-dev protobuf-compiler
           sudo apt-get install -y libopencv-dev && sudo ln -s /usr/include/opencv4/opencv2 /usr/include/opencv2
           sudo pip install -r extra/requirements.txt
 

backend/cpp/llama/CMakeLists.txt

@@ -5,11 +5,16 @@ set(_PROTOBUF_LIBPROTOBUF libprotobuf)
 set(_REFLECTION grpc++_reflection)
 
 find_package(absl REQUIRED)
-find_package(Protobuf CONFIG REQUIRED)
 find_package(gRPC CONFIG REQUIRED)
 find_program(_PROTOBUF_PROTOC protoc)
 set(_GRPC_GRPCPP grpc++)
 find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)
+
+# find_package(Protobuf CONFIG REQUIRED) is not working, see:
+# https://gitlab.kitware.com/cmake/cmake/-/issues/24321
+set(CMAKE_FIND_PACKAGE_PREFER_CONFIG 1)
+find_package(Protobuf)
+
 include_directories(${CMAKE_CURRENT_BINARY_DIR})
 include_directories(${Protobuf_INCLUDE_DIRS})