⬆️ Require CMake 3.28 and reduce dependency builds

AGENTS.md

@@ -39,7 +39,7 @@
 - Targets Linux (glibc 2.28+), macOS (11.0+), and Windows on x86_64 and arm64
   architectures
 - C++20
-- CMake 3.24+
+- CMake 3.28+
 - `FetchContent` for dependency management (configured in
   `cmake/ExternalDependencies.cmake`)
 - `clang-format` and `clang-tidy` for formatting/linting (see `.clang-format`

CMakeLists.txt

@@ -7,14 +7,15 @@
 # Licensed under the MIT License
 
 # set required cmake version
-cmake_minimum_required(VERSION 3.24...4.4)
+cmake_minimum_required(VERSION 3.28...4.4)
 
 project(
   mqt-ddsim
   LANGUAGES C CXX
   DESCRIPTION "MQT DDSIM - A quantum circuit simulator based on decision diagrams")
 
 set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_SCAN_FOR_MODULES OFF)
 
 option(BUILD_MQT_DDSIM_BINDINGS "Build the MQT DDSIM Python bindings" OFF)
 if(BUILD_MQT_DDSIM_BINDINGS)
@@ -49,18 +50,6 @@ option(BUILD_MQT_DDSIM_TESTS "Also build tests for the MQT DDSIM project"
        ${MQT_DDSIM_MASTER_PROJECT})
 option(BUILD_MQT_DDSIM_CLI "Build the MQT DDSIM command line interface" ${MQT_DDSIM_MASTER_PROJECT})
 
-# on macOS with GCC, disable module scanning
-# https://www.reddit.com/r/cpp_questions/comments/1kwlkom/comment/ni5angh/
-if(CMAKE_SYSTEM_NAME STREQUAL "Darwin" AND CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-  if(CMAKE_VERSION VERSION_GREATER_EQUAL "3.28")
-    set(CMAKE_CXX_SCAN_FOR_MODULES OFF)
-  else()
-    message(WARNING "CMake 3.28+ is required to disable C++ module scanning on macOS with GCC. "
-                    "Current version: ${CMAKE_VERSION}. "
-                    "Consider upgrading CMake to avoid potential build issues.")
-  endif()
-endif()
-
 include(cmake/ExternalDependencies.cmake)
 
 # set the include directory for the build tree

README.md

@@ -164,7 +164,7 @@ print(counts)
 ## System Requirements and Building
 
 Building the project requires a C++ compiler with support for C++20 and CMake
-3.24 or newer. For details on how to build the project, please refer to the
+3.28 or newer. For details on how to build the project, please refer to the
 [documentation](https://mqt.readthedocs.io/projects/ddsim). Building (and
 running) is continuously tested under Linux, macOS, and Windows using the
 [latest available system versions for GitHub Actions](https://github.com/actions/runner-images).

UPGRADING.md

@@ -6,7 +6,8 @@ of changes including minor and patch releases, please refer to the
 
 ## [Unreleased]
 
-This release updates the minimum required `mqt-core` version to 3.10.0.
+This release updates the minimum required `mqt-core` version to 3.10.0 and
+requires CMake 3.28 or newer.
 
 ### macOS support
 

cmake/ExternalDependencies.cmake

@@ -46,17 +46,14 @@ FetchContent_Declare(
   mqt-core
   GIT_REPOSITORY https://github.com/${MQT_CORE_REPO_OWNER}/core.git
   GIT_TAG ${MQT_CORE_REV}
-  FIND_PACKAGE_ARGS ${MQT_CORE_MINIMUM_VERSION})
+  EXCLUDE_FROM_ALL FIND_PACKAGE_ARGS ${MQT_CORE_MINIMUM_VERSION})
 list(APPEND FETCH_PACKAGES mqt-core)
 
 set(JSON_VERSION
     3.12.0
     CACHE STRING "nlohmann_json version")
 set(JSON_URL https://github.com/nlohmann/json/releases/download/v${JSON_VERSION}/json.tar.xz)
-set(JSON_SystemInclude
-    ON
-    CACHE INTERNAL "Treat the library headers like system headers")
-FetchContent_Declare(nlohmann_json URL ${JSON_URL} FIND_PACKAGE_ARGS ${JSON_VERSION})
+FetchContent_Declare(nlohmann_json URL ${JSON_URL} SYSTEM FIND_PACKAGE_ARGS ${JSON_VERSION})
 list(APPEND FETCH_PACKAGES nlohmann_json)
 
 if(BUILD_MQT_DDSIM_TESTS)
@@ -84,7 +81,7 @@ set(TF_VERSION
     3.7.0
     CACHE STRING "Taskflow version")
 set(TF_URL https://github.com/taskflow/taskflow/archive/refs/tags/v${TF_VERSION}.tar.gz)
-FetchContent_Declare(taskflow URL ${TF_URL} FIND_PACKAGE_ARGS)
+FetchContent_Declare(taskflow URL ${TF_URL} SYSTEM FIND_PACKAGE_ARGS)
 list(APPEND FETCH_PACKAGES taskflow)
 
 if(BUILD_MQT_DDSIM_CLI)

docs/contributing.md

@@ -194,7 +194,7 @@ instructions on how to set up your development environment.
 
 Building the project requires a C++20-capable
 [C++ compiler](https://en.wikipedia.org/wiki/List_of_compilers#C++_compilers)
-and [CMake](https://cmake.org/) 3.24 or newer. As of August 2025, our CI
+and [CMake](https://cmake.org/) 3.28 or newer. As of August 2025, our CI
 pipeline on GitHub continuously tests the library across the following matrix of
 systems and compilers:
 

docs/installation.md

@@ -107,7 +107,7 @@ pip install mqt.ddsim --no-binary mqt.ddsim
 
 This requires a C++20-capable
 [C++ compiler](https://en.wikipedia.org/wiki/List_of_compilers#C++_compilers)
-and [CMake](https://cmake.org/) 3.24 or newer.
+and [CMake](https://cmake.org/) 3.28 or newer.
 
 ## Integrating MQT DDSIM into Your Project
 

src/CMakeLists.txt

@@ -26,11 +26,6 @@ if(NOT TARGET MQT::DDSim)
     PUBLIC MQT::CoreDD Taskflow nlohmann_json::nlohmann_json
     PRIVATE MQT::ProjectWarnings MQT::ProjectOptions)
 
-  # the following sets the SYSTEM flag for the include dirs of the taskflow libs
-  set_target_properties(
-    Taskflow PROPERTIES INTERFACE_SYSTEM_INCLUDE_DIRECTORIES
-                        $<TARGET_PROPERTY:Taskflow,INTERFACE_INCLUDE_DIRECTORIES>)
-
   # add MQT alias
   add_library(MQT::DDSim ALIAS ${MQT_DDSIM_TARGET_NAME})
 endif()