message: qrenderdoc: Use QMAKE_EXECUTABLE if QT_QMAKE_EXECUTABLE is not defined
  Debian's debhelper automatically defines this variable during cross
  compilation builds.
diff: @@ -2,8 +2,12 @@ option(STATIC_QRENDERDOC "Compile qrenderdoc as static" OFF)
  option(QRENDERDOC_NO_CXX11_REGEX "Disable C++11 regex in scintilla" OFF)
  if( NOT DEFINED QT_QMAKE_EXECUTABLE )
  + if( DEFINED QMAKE_EXECUTABLE )
  + set( QT_QMAKE_EXECUTABLE "${QMAKE_EXECUTABLE}" )
  + else()
  set( QT_QMAKE_EXECUTABLE "qmake" )
  endif()
  +endif()
  set(QMAKE_QT5_COMMAND ${QT_QMAKE_EXECUTABLE} CACHE STRING "Command to run to invoke Qt5's qmake. Normally this is qmake, possibly with qtchooser, but might be qmake-qt5")
  set(RENDERDOC_SWIG_PACKAGE https://github.com/baldurk/swig/archive/renderdoc-modified-7.zip CACHE STRING "The location where RenderDoc's swig fork source can be found. By default points to the URL on github but can be pointed to a local file.")
  