From dda405f927aba3b753d7b98f63232f12b033bc2a Mon Sep 17 00:00:00 2001
From: Daniel Haag <121057143+denialhaag@users.noreply.github.com>
Date: Tue, 23 Jun 2026 22:33:32 +0200
Subject: [PATCH] =?UTF-8?q?=E2=AC=86=EF=B8=8F=20Update=20Eigen3=20to=20ver?=
 =?UTF-8?q?sion=205.0.1?=
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---
 cmake/ExternalDependencies.cmake | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/cmake/ExternalDependencies.cmake b/cmake/ExternalDependencies.cmake
index 70fd171..fb2675b 100644
--- a/cmake/ExternalDependencies.cmake
+++ b/cmake/ExternalDependencies.cmake
@@ -36,19 +36,24 @@ list(APPEND FETCH_PACKAGES mqt-core)
 
 # ---------------------------------------------------------------------------------Fetch Eigen3
 # cmake-format: off
-set(EIGEN_VERSION 3.4.0
+set(EIGEN_VERSION 5.0.1
         CACHE STRING "Eigen3 version")
 # cmake-format: on
 FetchContent_Declare(
   Eigen3
   GIT_REPOSITORY https://gitlab.com/libeigen/eigen.git
   GIT_TAG ${EIGEN_VERSION}
-  GIT_SHALLOW TRUE
-  # null is a non-existent subdirectory in Eigen3's repository, so add_subdirectory() becomes a
-  # no-op. This stops Eigen3's own CMakeLists.txt from running, which is only relevant for its
-  # documentation and tests.
-  SOURCE_SUBDIR null)
+  GIT_SHALLOW TRUE)
 list(APPEND FETCH_PACKAGES Eigen3)
+set(EIGEN_BUILD_TESTING
+    OFF
+    CACHE BOOL "Disable testing for Eigen")
+set(BUILD_TESTING
+    OFF
+    CACHE BOOL "Disable general testing")
+set(EIGEN_BUILD_DOC
+    OFF
+    CACHE BOOL "Disable documentation build for Eigen")
 
 if(BUILD_MQT_DEBUGGER_TESTS)
   set(gtest_force_shared_crt
@@ -65,8 +70,5 @@ endif()
 # Make all declared dependencies available.
 FetchContent_MakeAvailable(${FETCH_PACKAGES})
 
-add_library(Eigen3::Eigen INTERFACE IMPORTED)
-set_target_properties(Eigen3::Eigen PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${eigen3_SOURCE_DIR}")
-
 # Hide Eigen3 warnings
 get_target_property(Eigen3_Includes Eigen3::Eigen INTERFACE_INCLUDE_DIRECTORIES)