/usr/include/CLucene/index/ is in libclucene-dev 0.9.21b-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/CLucene/index/CompoundFile.h
/usr/include/CLucene/index/DocumentWriter.h
/usr/include/CLucene/index/FieldInfo.h
/usr/include/CLucene/index/FieldInfos.h
/usr/include/CLucene/index/FieldsReader.h
/usr/include/CLucene/index/FieldsWriter.h
/usr/include/CLucene/index/IndexModifier.h
/usr/include/CLucene/index/IndexReader.h
/usr/include/CLucene/index/IndexWriter.h
/usr/include/CLucene/index/MultiReader.h
/usr/include/CLucene/index/SegmentHeader.h
/usr/include/CLucene/index/SegmentInfos.h
/usr/include/CLucene/index/SegmentMergeInfo.h
/usr/include/CLucene/index/SegmentMergeQueue.h
/usr/include/CLucene/index/SegmentMerger.h
/usr/include/CLucene/index/SegmentTermEnum.h
/usr/include/CLucene/index/Term.h
/usr/include/CLucene/index/TermInfo.h
/usr/include/CLucene/index/TermInfosReader.h
/usr/include/CLucene/index/TermInfosWriter.h
/usr/include/CLucene/index/TermVector.h
/usr/include/CLucene/index/Terms.h