Index: ament_cmake_core/cmake/core/python.cmake
===================================================================
--- ament_cmake_core.orig/cmake/core/python.cmake
+++ ament_cmake_core/cmake/core/python.cmake
@@ -17,6 +17,10 @@
 # Example:
 #   find_package(Python3 3.8 REQUIRED)
 #   find_package(ament_cmake REQUIRED)
+ 
+if (CMAKE_GENTOO_BUILD OR CMAKE_BUILD_TYPE STREQUAL Gentoo)
+  set(Python3_FIND_UNVERSIONED_NAMES FIRST)
+endif()
 if(NOT TARGET Python3::Interpreter)
   find_package(Python3 REQUIRED COMPONENTS Interpreter)
 endif()