使用cmake交叉编译QT4应用程序

Question

我正在尝试在Ubuntu 18.04计算机中使用CMake交叉编译QT4应用程序。 以下是我在CMakeLists.txt中使用的相关行。

set(CMAKE_PREFIX_PATH "/opt/CrossPlatform/Qt-4.8.6/")
FIND_PACKAGE(Qt4 4.8.6 REQUIRED PATHS /opt/CrossPlatform/Qt-4.8.6/)
if(NOT Qt4_FOUND)
message(FATAL_ERROR "Package Qt4.8 not found")
endif()

SET(CMAKE_AUTOMOC ON)
INCLUDE(${QT_USE_FILE})

在运行cmake时，出现以下错误：

 Could not find a package configuration file provided by "Qt4" (requested
  version 4.8.6) with any of the following names:

    Qt4Config.cmake
    qt4-config.cmake

  Add the installation prefix of "Qt4" to CMAKE_PREFIX_PATH or set "Qt4_DIR"
  to a directory containing one of the above files.  If "Qt4" provides a
  separate development package or SDK, be sure it has been installed.

如何更正？