Find pybind11 in python/CMakeLists.txt

Signed-off-by: Steve Peters <[email protected]>

CMakeLists.txt

@@ -58,19 +58,11 @@ if (SKIP_PYBIND11)
   message(STATUS "SKIP_PYBIND11 set - disabling python bindings")
   find_package(Python3 COMPONENTS Interpreter)
 else()
-  find_package(Python3 COMPONENTS Interpreter Development)
+  find_package(Python3
+    COMPONENTS Interpreter
+    OPTIONAL_COMPONENTS Development)
   if (NOT Python3_Development_FOUND)
     GZ_BUILD_WARNING("Python development libraries are missing: Python interfaces are disabled.")
-  else()
-    set(PYBIND11_PYTHON_VERSION 3)
-    find_package(pybind11 2.4 CONFIG QUIET)
-
-    if (pybind11_FOUND)
-      message (STATUS "Searching for pybind11 - found version ${pybind11_VERSION}.")
-    else()
-      GZ_BUILD_WARNING("pybind11 is missing: Python interfaces are disabled.")
-      message (STATUS "Searching for pybind11 - not found.")
-    endif()
   endif()
 endif()
 
@@ -164,7 +156,7 @@ add_subdirectory(conf)
 #============================================================================
 # gz transport python bindings
 #============================================================================
-if (pybind11_FOUND AND NOT SKIP_PYBIND11)
+if (Python3_Development_FOUND AND NOT SKIP_PYBIND11)
   add_subdirectory(python)
 endif()
 

python/CMakeLists.txt

@@ -3,14 +3,25 @@ if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR)
   cmake_minimum_required(VERSION 3.22.1)
   set(GZ_TRANSPORT_VER 14)
   project(gz-transport${GZ_TRANSPORT_VER}-python VERSION ${GZ_TRANSPORT_VER})
-  find_package(Python3 COMPONENTS Interpreter Development REQUIRED)
-  find_package(pybind11 REQUIRED)
   find_package(gz-transport${PROJECT_VERSION_MAJOR} REQUIRED)
   set(PROJECT_LIBRARY_TARGET_NAME "gz-transport${PROJECT_VERSION_MAJOR}::gz-transport${PROJECT_VERSION_MAJOR}")
+  # require python dependencies to be found
+  find_package(Python3 COMPONENTS Interpreter Development REQUIRED)
+  set(CMAKE_REQUIRE_FIND_PACKAGE_pybind11 TRUE)
   include(GNUInstallDirs)
   include(CTest)
 endif()
 
+set(PYBIND11_PYTHON_VERSION 3)
+find_package(pybind11 2.4 CONFIG QUIET)
+
+if (pybind11_FOUND)
+  message (STATUS "Searching for pybind11 - found version ${pybind11_VERSION}.")
+else()
+  message(WARNING "pybind11 is missing: Python interfaces are disabled.")
+  return()
+endif()
+
 if(USE_SYSTEM_PATHS_FOR_PYTHON_INSTALLATION)
   if(NOT Python3_SITEARCH)
     # Get install variable from Python3 module