File fix-cmake-target-generator-for-sysroot.patch of Package cmake

--- a/Source/cmExportFileGenerator.cxx	2021-04-22 15:19:25.844345773 +0200
+++ b/Source/cmExportFileGenerator.cxx	2021-04-26 12:14:46.566045984 +0200
@@ -1167,7 +1167,7 @@
   os << "# Loop over all imported files and verify that they actually exist\n"
         "foreach(target ${_IMPORT_CHECK_TARGETS} )\n"
         "  foreach(file ${_IMPORT_CHECK_FILES_FOR_${target}} )\n"
-        "    if(NOT EXISTS \"${file}\" )\n"
+        "    if(NOT EXISTS \"${CMAKE_SYSROOT}${file}\" )\n"
         "      message(FATAL_ERROR \"The imported target \\\"${target}\\\""
         " references the file\n"
         "   \\\"${file}\\\"\n"