cmake: fail if Python is not found

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 526bec1..61c9b47 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -145,6 +145,9 @@ set(PythonInterp_FIND_VERSION 3)
 set(PythonInterp_FIND_VERSION_COUNT 1)
 set(PythonInterp_FIND_VERSION_MAJOR 3)
 include(FindPythonInterp)
+if(NOT PYTHON_EXECUTABLE)
+  message(FATAL_ERROR "Please install Python (version 3 or higher).")
+endif()
 
 if (APPLE)
   set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib")