NON_INDEX_XML_FILES = $(filter-out man/systemd.index.xml,$(XML_FILES))
SOURCE_XML_FILES = $(filter-out man/systemd.directives.xml,$(NON_INDEX_XML_FILES))
NON_INDEX_XML_FILES = $(filter-out man/systemd.index.xml,$(XML_FILES))
SOURCE_XML_FILES = $(filter-out man/systemd.directives.xml,$(NON_INDEX_XML_FILES))