Invalid path in urdfdom_INCLUDE_DIRS on Windows installation using vcpkg

[jslee02]

I am encountering an issue while installing urdfdom using vcpkg on Windows. The urdfdom-config.cmake file that is generated and installed contains the following issue: (CI log):

if (urdfdom_CONFIG_INCLUDED)
  return()
endif()
set(urdfdom_CONFIG_INCLUDED TRUE)

set(urdfdom_INCLUDE_DIRS "${CMAKE_CURRENT_LIST_DIR}/../../include" "${_IMPORT_PREFIX}/include")

foreach(lib urdfdom_sensor;urdfdom_model_state;urdfdom_model;urdfdom_world)
  set(onelib "${lib}-NOTFOUND")
  find_library(onelib ${lib}
      PATHS "${CMAKE_CURRENT_LIST_DIR}/../../lib"
    NO_DEFAULT_PATH
    )
  if(NOT onelib)
    message(FATAL_ERROR "Library '${lib}' in package urdfdom is not installed properly")
  endif()
  list(APPEND urdfdom_LIBRARIES ${onelib})
endforeach()


foreach(dep urdfdom_headers;console_bridge)
  if(NOT ${dep}_FOUND)
    find_package(${dep})
  endif()
  list(APPEND urdfdom_INCLUDE_DIRS ${${dep}_INCLUDE_DIRS})
  list(APPEND urdfdom_LIBRARIES ${${dep}_LIBRARIES})
endforeach()

In line 6 of the urdfdom-config.cmake file, the variable urdfdom_INCLUDE_DIRS contains ${_IMPORT_PREFIX}/include, which is /include because _IMPORT_PREFIX is not defined for some reason. This seems to be causing a problem with TinyXML_INCLUDE_DIRS not being correctly defined on Windows. The relevant section of the urdfdom-config.cmake file is:

urdfdom/cmake/urdfdom-config.cmake.in

Line 6 in 0da4b20

set(@PKG_NAME@_INCLUDE_DIRS "@CMAKE_INSTALL_PREFIX@/include" "@TinyXML_INCLUDE_DIRS@")

where TinyXML_INCLUDE_DIRS is defined in the following way:

urdfdom/cmake/FindTinyXML.cmake

Lines 56 to 74 in 0da4b20

	# Find headers and libraries
	find_path(TinyXML_INCLUDE_DIR NAMES tinyxml.h PATH_SUFFIXES "tinyxml" ${TinyXML_INCLUDE_PATH})
	find_library(TinyXML_LIBRARY NAMES tinyxml PATH_SUFFIXES "tinyxml" ${TinyXML_LIBRARY_PATH})
	mark_as_advanced(TinyXML_INCLUDE_DIR
	TinyXML_LIBRARY)
	# Output variables generation
	include(FindPackageHandleStandardArgs)
	find_package_handle_standard_args(TinyXML DEFAULT_MSG TinyXML_LIBRARY
	TinyXML_INCLUDE_DIR)
	set(TinyXML_FOUND ${TINYXML_FOUND}) # Enforce case-correctness: Set appropriately cased variable...
	unset(TINYXML_FOUND) # ...and unset uppercase variable generated by find_package_handle_standard_args
	if(TinyXML_FOUND)
	set(TinyXML_INCLUDE_DIRS ${TinyXML_INCLUDE_DIR})
	set(TinyXML_LIBRARIES ${TinyXML_LIBRARY})
	endif()

This issue is related to dartsim/dart#1365