From: Greg Landrum <greg.landrum@gmail.com>
Date: Wed, 2 Sep 2026 18:10:13 +0200
Subject: improved handling of finding eigen (#9543)
Origin: upstream, https://github.com/rdkit/rdkit/commit/d8ce92b61ce356bc2764e13f0d4b9a5df48094c5

* improved handling of finding eigen

Fixes #8896
---
 CMakeLists.txt | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -407,9 +407,9 @@ else(RDK_BUILD_PYTHON_WRAPPERS)
   find_package(Boost ${RDK_BOOST_VERSION} REQUIRED CONFIG)
 endif(RDK_BUILD_PYTHON_WRAPPERS)
 
-find_package(Eigen3)
+find_package(Eigen3 NO_MODULE)
 if(RDK_BUILD_DESCRIPTORS3D)
-  if(NOT EIGEN3_FOUND)
+  if(NOT TARGET Eigen3::Eigen)
     add_subdirectory(External/Eigen)
   endif()
   target_compile_definitions(rdkit_base INTERFACE "-DRDK_BUILD_DESCRIPTORS3D")
