cmake build failed on macos catalina 10.15 - macos

Question

I have recently installed macos catalina with Xcode 11.1 and updated cmake, clang and llvm
sudo rm -rf /Library/Developer/CommandLineTools
xcode-select --install
$ cmake --version
cmake version 3.15.4
$ which cmake
/usr/local/bin/cmake
$ clang --version
Apple clang version 11.0.0 (clang-1100.0.33.8)
Target: x86_64-apple-darwin19.0.0
Thread model: posix
InstalledDir: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin
$ which clang
/usr/bin/clang
The CMakeLists.txt looks as bellow:
cmake_minimum_required(VERSION 3.14)
project("ROZZETA" VERSION 0.0.1 LANGUAGES C)
# Allow us to import cmake scripts from ./cmake
set(CMAKE_C_STANDARD 11)
set(CMAKE_C_STANDARD_REQUIRED ON)
set(CMAKE_C_EXTENSIONS OFF)
set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}")
# Compiler flags
set(CMAKE_C_COMPILER /usr/bin/clang CACHE PATH "")
find_package(GMP REQUIRED)
add_executable(Rozzeta main.c)
target_link_libraries(Rozzeta gmp libgmp libgmp.a)
cmake detected gmp successfully :
/usr/local/bin/cmake -DCMAKE_BUILD_TYPE=Debug -DCMAKE_C_COMPILER=/usr/bin/clang -DCMAKE_CXX_COMPILER=c++ -G "CodeBlocks - Unix Makefiles" /<path to project>
-- The C compiler identification is AppleClang 11.0.0.11000033
-- Check for working C compiler: /usr/bin/clang
-- Check for working C compiler: /usr/bin/clang -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Using toolchain file: .
-- Found GMP: /usr/local/include/gmp.h and /usr/local/lib/libgmp.a
-- Configuring done
-- Generating done
build failed :
cmake --build .
Scanning dependencies of target Rozzeta
[ 50%] Building C object CMakeFiles/Rozzeta.dir/main.c.o
/Users/gajaka/CLionProjects/Rozzeta/main.c:4:10: fatal error: 'gmp.h' file not found
#include <gmp.h>
^~~~~~~
1 error generated.
make[2]: *** [CMakeFiles/Rozzeta.dir/main.c.o] Error 1
make[1]: *** [CMakeFiles/Rozzeta.dir/all] Error 2
make: *** [all] Error 2
I have compiled manually with:
cc main.c -lgmp
Anyone can help me with this ?
Many thanks in advance

Answer 1

It was very frustrating for me! I am personally using CLion from jetbrains, while tried to build old codes written in C/C++, it's giving me error because MacOS 10.15, Catalina removed the C headers pkg used to be in Mojave. So, found another way around and tried.
If you have installed XCode 11.1, then open the terminal and run the following command:
xcode-select --install
then,
sudo ln -s /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/* /usr/local/include/
Now, you are good to go. Try to build using cmake.

Answer 2

If you're calling find_package(GMP ...) in your CMake file, why not use the GMP-specific variables it populates? It looks like CMake successfully finds GMP installed on your system (based on your CMake log), so try using the GMP_* variables that should be populated:
cmake_minimum_required(VERSION 3.14)
project("ROZZETA" VERSION 0.0.1 LANGUAGES C)
# Allow us to import cmake scripts from ./cmake
set(CMAKE_C_STANDARD 11)
set(CMAKE_C_STANDARD_REQUIRED ON)
set(CMAKE_C_EXTENSIONS OFF)
set(CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}")
# Compiler flags
set(CMAKE_C_COMPILER /usr/bin/clang CACHE PATH "")
find_package(GMP REQUIRED)
add_executable(Rozzeta main.c)
# Use the populated GMP variables here.
target_include_directories(Rozzeta PRIVATE ${GMP_INCLUDE_DIR})
target_link_libraries(Rozzeta PRIVATE ${GMP_LIB})

Answer 3

after
xcode-select --install
I got a clang but no cmake so I did
brew install cmake
which installed cmake for Catalina.

Answer 4

In order to compile programs with cmake and XCode's toolchain in Mac OS 10.15 (Catalina) you must install xcode command line utility tools + make some additional symlinks (#Roy said about it, but forgot to mention other two):
$ xcode-select --install
$ sudo ln -s /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/* /usr/local/include/
$ for i in {Platforms,Toolchains,Tools}; do sudo ln -sn /Applications/Xcode.app/Contents/Developer/$i /Library/Developer/CommandLineTools/$i; done