Only if PROJECT_IS_TOP_LEVEL use project_options (#139)

Author: ClausKlein

CMakeLists.txt

@@ -40,7 +40,9 @@ option(
 include(GNUInstallDirs)
 set(INSTALL_CONFIGDIR ${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME})
 
-if(NOT BEMAN_EXECUTION_ENABLE_INSTALL OR CMAKE_SKIP_INSTALL_RULES)
+if(PROJECT_IS_TOP_LEVEL AND NOT BEMAN_EXECUTION_ENABLE_INSTALL OR CMAKE_SKIP_INSTALL_RULES)
+  set(CMAKE_SKIP_INSTALL_RULES ON)
+
   include(FetchContent)
 
   # Add project_options from https://github.com/aminya/project_options

tests/beman/execution/CMakeLists.txt

@@ -114,6 +114,7 @@ if(PROJECT_IS_TOP_LEVEL)
   if(beman_execution_FOUND)
     set(execution_tests exec-awaitable.test) # only one sample to save time! CK
   else()
+    set(BEMAN_EXECUTION_ENABLE_INSTALL ON)
     add_subdirectory(../../.. beman_execution)
 
     include(CMakePrintHelpers)