/usr/lib/x86_64-linux-gnu/ is in libogre-1.9-dev 1.9.0+dfsg1-4.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/OGRE-Overlay.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/OGRE-Terrain.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/OGRE-RTShaderSystem.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/OGRE-Volume.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/OGRE.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/OGRE-PCZ.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/OGRE-Property.pc
/usr/lib/x86_64-linux-gnu/pkgconfig/OGRE-Paging.pc
/usr/lib/x86_64-linux-gnu/libOgrePaging.so
/usr/lib/x86_64-linux-gnu/libOgreProperty.so
/usr/lib/x86_64-linux-gnu/libOgreOverlay.so
/usr/lib/x86_64-linux-gnu/libOgreRTShaderSystem.so
/usr/lib/x86_64-linux-gnu/libOgreTerrain.so
/usr/lib/x86_64-linux-gnu/libOgreVolume.so
/usr/lib/x86_64-linux-gnu/libOgreMain.so