Building with Cmake Fetch Content Fails when including gRPC

[ctriley]

What language and solver does this apply to?
C++ / all

Describe the problem you are trying to solve.
I want to build a super-project that includes absl, gRPC and ortools. However, I'm running into dependency conflicts like:

CMake Error at cmake-build-debug/_deps/absl-src/CMake/AbseilHelpers.cmake:318 (add_library):
add_library cannot create target "atomic_hook" because another target with
the same name already exists. The existing target is an interface library
created in source directory

It looks like a similar issue occurred a few years ago #2219

Here is my cmakelists.txt

cmake_minimum_required(VERSION 3.26)
project(google_example)

set(CMAKE_CXX_STANDARD 17)

SET(ABSL_PROPAGATE_CXX_STD ON)
SET(ABSL_BUILD_TESTING OFF)
set(CMAKE_INCLUDE_CURRENT_DIR OFF)
set(CMAKE_THREAD_LIBS_INIT "-lpthread")
set(CMAKE_HAVE_THREADS_LIBRARY 1)
set(CMAKE_USE_WIN32_THREADS_INIT 0)
set(CMAKE_USE_PTHREADS_INIT 1)
set(THREADS_PREFER_PTHREAD_FLAG ON)
include(FetchContent)
set(FETCHCONTENT_QUIET OFF)
set(ABSL_ENABLE_INSTALL ON)
set(gRPC_SSL_PROVIDER package)
FetchContent_Declare(
        gRPC
        GIT_REPOSITORY https://github.com/grpc/grpc
        GIT_TAG        v1.59.2
)
FetchContent_MakeAvailable(gRPC)
set(_PROTOBUF_LIBPROTOBUF libprotobuf)
set(_REFLECTION grpc++_reflection)
set(_PROTOBUF_PROTOC $<TARGET_FILE:protoc>)
set(_GRPC_GRPCPP grpc++)
if(CMAKE_CROSSCOMPILING)
    find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)
else()
    set(_GRPC_CPP_PLUGIN_EXECUTABLE $<TARGET_FILE:grpc_cpp_plugin>)
endif()

message("Neither Gurobi nor Cplex was found." )
FetchContent_Declare(
        ortools
        GIT_REPOSITORY https://github.com/google/or-tools.git
        GIT_TAG        stable
)
set(BUILD_SHARED_LIBS OFF)
set(BUILD_DEPS ON)
set(BUILD_SAMPLES OFF)
set(BUILD_EXAMPLES OFF)
FetchContent_MakeAvailable(ortools)
add_definitions(-DORTOOLS)
include_directories(${ortools_SOURCE_DIR})
include_directories(${ortools_BINARY_DIR})
include_directories(${absl_SOURCE_DIR})
include_directories(${protobuf_SOURCE_DIR}/../src)

add_executable(google_example main.cpp)
target_link_libraries(google_example absl::string gRPC ortools::ortools)

Describe the solution you'd like
Ideally, before trying to build the required libraries, we would check builddir/_deps/ for existing targets.

Describe alternatives you've considered
I could install the packages outside of the configure/build step, but this isn't as nice as having the configure/build step do everything.

[ctriley]

Update:

I'm trying to explicitly replace find_package calls using the OVERRIDE_FIND_PACKAGE option. This seems to work for the protobuf, grpc, and absl packages. However, I have issues with or-tools when setting build dependencies to ON.

CMake Error at cmake-build-debug/_deps/re2-src/CMakeLists.txt:137 (add_library):
add_library cannot create target "re2" because another target with the same
name already exists. The existing target is a static library created in
source directory

Therefore, I'm trying a different approach, setting build dependencies to off, and manually specifying the deps I need to build (cmake below). However, I still get an error:

CMake Error at cmake-build-debug/_deps/ortools-src/cmake/cpp.cmake:155 (target_link_libraries):
Target "ortools" links to: Coin::CbcSolver

Which is strange because I explicitly told ortools to build CoinUtils.

cmake_minimum_required(VERSION 3.26)
project(google_example)

set(CMAKE_CXX_STANDARD 17)
cmake_policy(SET CMP0022 NEW)
cmake_policy(SET CMP0077 NEW)
cmake_policy(SET CMP0079 NEW)

SET(ABSL_PROPAGATE_CXX_STD ON)
SET(ABSL_BUILD_TESTING OFF)
set(CMAKE_INCLUDE_CURRENT_DIR OFF)
set(CMAKE_THREAD_LIBS_INIT "-lpthread")
set(CMAKE_HAVE_THREADS_LIBRARY 1)
set(CMAKE_USE_WIN32_THREADS_INIT 0)
set(CMAKE_USE_PTHREADS_INIT 1)
set(THREADS_PREFER_PTHREAD_FLAG ON)
find_package(Threads REQUIRED)
set(sublibs ${sublibs} Threads::Threads)

include(FetchContent)
set(FETCHCONTENT_QUIET OFF)
set(ABSL_ENABLE_INSTALL ON)

get_directory_property(old_dir_compile_options COMPILE_OPTIONS)
add_compile_options(-w)
FetchContent_Declare(
        absl
        GIT_REPOSITORY https://github.com/abseil/abseil-cpp.git
        GIT_TAG 20230802.1
        OVERRIDE_FIND_PACKAGE
)
FetchContent_MakeAvailable(absl)


FetchContent_Declare(Protobuf
        GIT_REPOSITORY https://github.com/protocolbuffers/protobuf.git
        GIT_TAG        v24.4
        SOURCE_SUBDIR  cmake
        OVERRIDE_FIND_PACKAGE
)
FetchContent_MakeAvailable(Protobuf)

set(gRPC_SSL_PROVIDER package)
set(gRPC_ZLIB_PROVIDER=package)
FetchContent_Declare(
        gRPC
        GIT_REPOSITORY https://github.com/grpc/grpc
        GIT_TAG        v1.59.2
        OVERRIDE_FIND_PACKAGE
)
FetchContent_MakeAvailable(gRPC)
set(_PROTOBUF_LIBPROTOBUF libprotobuf)
set(_REFLECTION grpc++_reflection)
set(_PROTOBUF_PROTOC $<TARGET_FILE:protoc>)
set(_GRPC_GRPCPP grpc++)
if(CMAKE_CROSSCOMPILING)
    find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)
else()
    set(_GRPC_CPP_PLUGIN_EXECUTABLE $<TARGET_FILE:grpc_cpp_plugin>)
endif()

set(BUILD_SHARED_LIBS OFF)
set(BUILD_SAMPLES OFF)
set(BUILD_EXAMPLES OFF)
set(BUILD_DEPS OFF) # if you turn this on, remove the following build lines
set(BUILD_Eigen3 ON)
set(BUILD_CoinUtils ON)
set(BUILD_SCIP ON)
FetchContent_Declare(
        ortools
        GIT_REPOSITORY https://github.com/google/or-tools.git
        GIT_TAG        stable
)

FetchContent_MakeAvailable(ortools)
add_definitions(-DORTOOLS)
include_directories(${ortools_SOURCE_DIR})
include_directories(${ortools_BINARY_DIR})
include_directories(${absl_SOURCE_DIR})
include_directories(${protobuf_SOURCE_DIR}/../src)
set_directory_properties(PROPERTIES COMPILE_OPTIONS "${old_dir_compile_options}")
add_executable(google_example main.cpp)
target_link_libraries(google_example absl::strings grpc)

[ctriley]

Okay, finally figured it out. Leaving here for posterity and closing the issue.

cmake_minimum_required(VERSION 3.26)
project(google_example)

set(CMAKE_CXX_STANDARD 17)
cmake_policy(SET CMP0022 NEW)
cmake_policy(SET CMP0077 NEW)
cmake_policy(SET CMP0079 NEW)

SET(ABSL_PROPAGATE_CXX_STD ON)
SET(ABSL_BUILD_TESTING OFF)
set(CMAKE_INCLUDE_CURRENT_DIR OFF)
set(CMAKE_THREAD_LIBS_INIT "-lpthread")
set(CMAKE_HAVE_THREADS_LIBRARY 1)
set(CMAKE_USE_WIN32_THREADS_INIT 0)
set(CMAKE_USE_PTHREADS_INIT 1)
set(THREADS_PREFER_PTHREAD_FLAG ON)
find_package(Threads REQUIRED)
set(sublibs ${sublibs} Threads::Threads)

include(FetchContent)
set(FETCHCONTENT_QUIET OFF)
set(ABSL_ENABLE_INSTALL ON)

get_directory_property(old_dir_compile_options COMPILE_OPTIONS)
add_compile_options(-w)
FetchContent_Declare(
        absl
        GIT_REPOSITORY https://github.com/abseil/abseil-cpp.git
        GIT_TAG 20230802.1
        OVERRIDE_FIND_PACKAGE
)
FetchContent_MakeAvailable(absl)


FetchContent_Declare(Protobuf
        GIT_REPOSITORY https://github.com/protocolbuffers/protobuf.git
        GIT_TAG        v24.4
        SOURCE_SUBDIR  cmake
        OVERRIDE_FIND_PACKAGE
)
FetchContent_MakeAvailable(Protobuf)

set(gRPC_SSL_PROVIDER package)
set(gRPC_ZLIB_PROVIDER=package)
FetchContent_Declare(
        gRPC
        GIT_REPOSITORY https://github.com/grpc/grpc
        GIT_TAG        v1.59.2
        OVERRIDE_FIND_PACKAGE
)
FetchContent_MakeAvailable(gRPC)
set(_PROTOBUF_LIBPROTOBUF libprotobuf)
set(_REFLECTION grpc++_reflection)
set(_PROTOBUF_PROTOC $<TARGET_FILE:protoc>)
set(_GRPC_GRPCPP grpc++)
if(CMAKE_CROSSCOMPILING)
    find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)
else()
    set(_GRPC_CPP_PLUGIN_EXECUTABLE $<TARGET_FILE:grpc_cpp_plugin>)
endif()

set(BUILD_SHARED_LIBS OFF)
set(BUILD_DEPS OFF)
set(BUILD_SAMPLES OFF)
set(BUILD_EXAMPLES OFF)
set(BUILD_Eigen3 ON)
set(BUILD_CoinUtils ON)
set(BUILD_Cbc ON)
set(BUILD_Osi ON)
set(BUILD_Clp ON)
set(BUILD_Cgl ON)
set(BUILD_SCIP ON)
FetchContent_Declare(
        ortools
        GIT_REPOSITORY https://github.com/google/or-tools.git
        GIT_TAG        stable
)

FetchContent_MakeAvailable(ortools)
add_definitions(-DORTOOLS)
include_directories(${ortools_SOURCE_DIR})
include_directories(${ortools_BINARY_DIR})
include_directories(${absl_SOURCE_DIR})
include_directories(${protobuf_SOURCE_DIR}/../src)
set_directory_properties(PROPERTIES COMPILE_OPTIONS "${old_dir_compile_options}")
add_executable(google_example main.cpp)
target_link_libraries(google_example absl::strings grpc)

[ctriley]

Actually, while the above passes the configure step, it does not compile as ortools cannot find absl libraries.

/Users/me/google-example/cmake-build-debug/_deps/ortools-src/ortools/sat/cuts.cc:79:24: error: no matching function for call to 'StrCat'
std::string result = absl::StrCat("CutData rhs=", rhs, "\n");
^~~~~~~~~~~~

[ctriley]

I got it to work. here is the final code

cmake_minimum_required(VERSION 3.24)
project(google_example)

set(CMAKE_CXX_STANDARD 17)
cmake_policy(SET CMP0022 NEW)
cmake_policy(SET CMP0042 NEW)
cmake_policy(SET CMP0068 NEW)
cmake_policy(SET CMP0077 NEW)
cmake_policy(SET CMP0079 NEW)

SET(ABSL_PROPAGATE_CXX_STD ON)
SET(ABSL_BUILD_TESTING OFF)
set(CMAKE_INCLUDE_CURRENT_DIR OFF)
set(CMAKE_THREAD_LIBS_INIT "-lpthread")
set(CMAKE_HAVE_THREADS_LIBRARY 1)
set(CMAKE_USE_WIN32_THREADS_INIT 0)
set(CMAKE_USE_PTHREADS_INIT 1)
set(THREADS_PREFER_PTHREAD_FLAG ON)
find_package(Threads REQUIRED)
set(sublibs ${sublibs} Threads::Threads)

include(FetchContent)
set(FETCHCONTENT_QUIET OFF)
set(ABSL_ENABLE_INSTALL ON)

get_directory_property(old_dir_compile_options COMPILE_OPTIONS)
add_compile_options(-w)
message(${CMAKE_CURRENT_LIST_DIR})

FetchContent_Declare(
        absl
        GIT_REPOSITORY https://github.com/abseil/abseil-cpp.git
        GIT_TAG 20230125.3
#        PATCH_COMMAND git apply --ignore-whitespace "${CMAKE_CURRENT_LIST_DIR}/abseil-cpp-20230125.3.patch"
        OVERRIDE_FIND_PACKAGE
)
FetchContent_MakeAvailable(absl)
include_directories(${absl_SOURCE_DIR})

set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
set(BUILD_GMOCK OFF CACHE BOOL "" FORCE)
set(BUILD_GTEST ON CACHE BOOL "" FORCE)
FetchContent_Declare(
        googletest
        GIT_REPOSITORY https://github.com/google/googletest.git
        GIT_TAG        v1.14.0
        OVERRIDE_FIND_PACKAGE
)
FetchContent_MakeAvailable(googletest)

set(RE2_BUILD_TESTING OFF)
FetchContent_Declare(
        re2
        GIT_REPOSITORY "https://github.com/google/re2.git"
        GIT_TAG "2023-07-01"
        OVERRIDE_FIND_PACKAGE
        #PATCH_COMMAND git apply --ignore-whitespace "${CMAKE_CURRENT_LIST_DIR}/../../patches/re2-2023-07-01.patch"
)
FetchContent_MakeAvailable(re2)
set(gRPC_RE2_PROVIDER package)

FetchContent_Declare(Protobuf
        GIT_REPOSITORY https://github.com/protocolbuffers/protobuf.git
        GIT_TAG        v24.4
        SOURCE_SUBDIR  cmake
        OVERRIDE_FIND_PACKAGE
)
FetchContent_MakeAvailable(Protobuf)

include_directories(${protobuf_SOURCE_DIR}/../src)
set(gRPC_SSL_PROVIDER package)
set(gRPC_ZLIB_PROVIDER package)
FetchContent_Declare(
        gRPC
        GIT_REPOSITORY https://github.com/grpc/grpc
        GIT_TAG        v1.59.2
        OVERRIDE_FIND_PACKAGE
)
FetchContent_MakeAvailable(gRPC)
set(_PROTOBUF_LIBPROTOBUF libprotobuf)
set(_REFLECTION grpc++_reflection)
set(_PROTOBUF_PROTOC $<TARGET_FILE:protoc>)
set(_GRPC_GRPCPP grpc++)
if(CMAKE_CROSSCOMPILING)
    find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)
else()
    set(_GRPC_CPP_PLUGIN_EXECUTABLE $<TARGET_FILE:grpc_cpp_plugin>)
endif()

set(BUILD_SHARED_LIBS OFF)
set(BUILD_DEPS OFF)
set(BUILD_SAMPLES OFF)
set(BUILD_EXAMPLES OFF)
set(BUILD_Eigen3 ON)
set(BUILD_CoinUtils ON)
set(BUILD_Cbc ON)
set(BUILD_Osi ON)
set(BUILD_Clp ON)
set(BUILD_Cgl ON)
set(BUILD_SCIP ON)
FetchContent_Declare(
        ortools
        GIT_REPOSITORY https://github.com/google/or-tools.git
        GIT_TAG        v9.7
)

FetchContent_MakeAvailable(ortools)
add_definitions(-DORTOOLS)
include_directories(${ortools_SOURCE_DIR})
include_directories(${ortools_BINARY_DIR})
set_directory_properties(PROPERTIES COMPILE_OPTIONS "${old_dir_compile_options}")
add_executable(google_example main.cpp)
target_link_libraries(google_example absl::strings grpc ortools::ortools)