/usr/include/osl/eval/ is in libosl-dev 0.6.0-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/osl/eval/concept.h
/usr/include/osl/eval/endgame/
/usr/include/osl/eval/endgame/attackDefense.h
/usr/include/osl/eval/endgame/attackKing.h
/usr/include/osl/eval/endgame/defenseKing.h
/usr/include/osl/eval/endgame/kingPieceTable.h
/usr/include/osl/eval/endgame/kingPieceValues.h
/usr/include/osl/eval/evalCompareLarger.h
/usr/include/osl/eval/evalTraits.h
/usr/include/osl/eval/minorPieceBonus.h
/usr/include/osl/eval/ml/
/usr/include/osl/eval/ml/evalStagePair.h
/usr/include/osl/eval/ml/king8.h
/usr/include/osl/eval/ml/kingTable.h
/usr/include/osl/eval/ml/majorPiece.h
/usr/include/osl/eval/ml/midgame.h
/usr/include/osl/eval/ml/minorPiece.h
/usr/include/osl/eval/ml/mobility.h
/usr/include/osl/eval/ml/openMidEndingEval.h
/usr/include/osl/eval/ml/pieceEval.h
/usr/include/osl/eval/ml/piecePair.h
/usr/include/osl/eval/ml/piecePairKing.h
/usr/include/osl/eval/ml/pieceStand.h
/usr/include/osl/eval/ml/pin.h
/usr/include/osl/eval/ml/progress.h
/usr/include/osl/eval/ml/weights.h
/usr/include/osl/eval/mobilityTable.h
/usr/include/osl/eval/pieceEval.h
/usr/include/osl/eval/pieceEval.tcc
/usr/include/osl/eval/ppair/
/usr/include/osl/eval/ppair/piecePairAssert.h
/usr/include/osl/eval/ppair/piecePairEval.h
/usr/include/osl/eval/ppair/piecePairEval.tcc
/usr/include/osl/eval/ppair/piecePairIndex.h
/usr/include/osl/eval/ppair/piecePairPieceEval.h
/usr/include/osl/eval/ppair/piecePairRawEval.h
/usr/include/osl/eval/ppair/piecePairTable.h
/usr/include/osl/eval/ppair/piecePairWithStand.h
/usr/include/osl/eval/ppair/piecePairWithStand.tcc
/usr/include/osl/eval/ppair/readme.h
/usr/include/osl/eval/progressEval.h
/usr/include/osl/eval/ptypeEvalTraits.h
/usr/include/osl/eval/readme.h
/usr/include/osl/eval/see.h