Basic CMakeLists.txt contents I often use in my projects...

CMakeLists.txt

cmake_minimum_required(VERSION 3.8)

project(FakeDev VERSION 0.1 LANGUAGES CXX)

set(CMAKE_EXPORT_COMPILE_COMMANDS Yes)

set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED Yes)
set(CMAKE_CXX_EXTENSIONS No)

if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
    message(STATUS "Setting build type to 'Debug' as none was specified.")
    set(CMAKE_BUILD_TYPE Debug CACHE STRING "Choose the type of build." FORCE)
    set_property(CACHE CMAKE_BUILD_TYPE PROPERTY STRINGS "Debug" "Release" "MinSizeRel" "RelWithDebInfo")
endif()

set(CMAKE_CXX_FLAGS "-Wall -Wextra -pedantic ${CMAKE_CXX_FLAGS}")
set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O2")
set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "${CMAKE_CXX_FLAGS_RELWITHDEBINFO} -Og")
set(CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL} -Os")
set(CMAKE_CXX_FLAGS_DEBUG "-Werror ${CMAKE_CXX_FLAGS_DEBUG} -Og")

message(STATUS "--------------- Overview of important CMake variables: ---------------")
message(STATUS "CMAKE_BUILD_TYPE: ${CMAKE_BUILD_TYPE}")
message(STATUS "CMAKE_CXX_STANDARD: ${CMAKE_CXX_STANDARD} (Required: ${CMAKE_CXX_STANDARD_REQUIRED})")
message(STATUS "CMAKE_EXPORT_COMPILE_COMMANDS: ${CMAKE_EXPORT_COMPILE_COMMANDS}")
message(STATUS "CMAKE_CXX_FLAGS: ${CMAKE_CXX_FLAGS}")
message(STATUS "CMAKE_CXX_FLAGS_DEBUG: ${CMAKE_CXX_FLAGS_DEBUG}")
message(STATUS "CMAKE_CXX_FLAGS_RELEASE: ${CMAKE_CXX_FLAGS_RELEASE}")
message(STATUS "CMAKE_CXX_FLAGS_MINSIZEREL: ${CMAKE_CXX_FLAGS_MINSIZEREL}")
message(STATUS "CMAKE_CXX_FLAGS_RELWITHDEBINFO: ${CMAKE_CXX_FLAGS_RELWITHDEBINFO}")
message(STATUS "CMAKE_INSTALL_PREFIX: ${CMAKE_INSTALL_PREFIX}")
message(STATUS "CMAKE_INCLUDE_PATH: ${CMAKE_INCLUDE_PATH}")
message(STATUS "CMAKE_LIBRARY_PATH: ${CMAKE_LIBRARY_PATH}")
message(STATUS "----------------------------------------------------------------------")
message(STATUS "Project name: ${CMAKE_PROJECT_NAME} (version ${PROJECT_VERSION})")
message(STATUS "CMAKE_GENERATOR: ${CMAKE_GENERATOR}")
message(STATUS "----------------------------------------------------------------------")

include_directories(include/)

###############################################################################################################

cmake_minimum_required(VERSION 3.9.0)

project(TicTacCpp VERSION 0.1 LANGUAGES CXX)

set(CMAKE_EXPORT_COMPILE_COMMANDS True
    CACHE BOOL "Export compile commands into compile_commands.json file?" FORCE)

include(GNUInstallDirs)

# Setting basic project configuration, properties...

include_directories(include)

if (NOT CMAKE_BUILD_TYPE)
  set(CMAKE_BUILD_TYPE Debug CACHE STRING "Choose project build type" FORCE)
  set_property(CACHE CMAKE_BUILD_TYPE
               PROPERTY STRINGS "Debug" "Release" "RelWithDebInfo" "MinSizeRel")
  message(STATUS "CMAKE_BUILD_TYPE not set; default: Debug")
endif ()

set(CMAKE_CXX_STANDARD          17)
set(CMAKE_CXX_STANDARD_REQUIRED True)
set(CMAKE_CXX_EXTENSIONS        False)
set(CMAKE_CXX_FLAGS             "${CMAKE_CXX_FLAGS} -Wall -Wextra")
set(CMAKE_CXX_FLAGS_DEBUG       "${CMAKE_CXX_FLAGS_DEBUG} -Og")

# TicTacCpp header files

set(TicTacCpp_HDRS
  include/TicTacCpp/TicTacCpp.hpp
)

# TicTacCpp source files

set(TicTacCpp_SRCS
  src/main.cpp
)

# Compile the 'main' executable (= the TicTacCpp game)

add_executable(main ${TicTacCpp_SRCS})