/usr/include/ is in libgegl-0.0-dev 0.0.22-2ubuntu3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/gegl-0.0/
/usr/include/gegl-0.0/operation/
/usr/include/gegl-0.0/operation/gegl-operation.h
/usr/include/gegl-0.0/gegl-simd.h
/usr/include/gegl-0.0/operation/gegl-operation-area-filter.h
/usr/include/gegl-0.0/operation/gegl-operation-composer.h
/usr/include/gegl-0.0/operation/gegl-operation-composer3.h
/usr/include/gegl-0.0/operation/gegl-operation-filter.h
/usr/include/gegl-0.0/operation/gegl-operation-meta.h
/usr/include/gegl-0.0/operation/gegl-operation-point-composer.h
/usr/include/gegl-0.0/operation/gegl-operation-point-composer3.h
/usr/include/gegl-0.0/operation/gegl-operation-point-filter.h
/usr/include/gegl-0.0/operation/gegl-operation-point-render.h
/usr/include/gegl-0.0/operation/gegl-operation-sink.h
/usr/include/gegl-0.0/operation/gegl-operation-source.h
/usr/include/gegl-0.0/operation/gegl-operation-temporal.h
/usr/include/gegl-0.0/gegl.h
/usr/include/gegl-0.0/gegl-utils.h
/usr/include/gegl-0.0/gegl-matrix.h
/usr/include/gegl-0.0/gegl-chant.h
/usr/include/gegl-0.0/gegl-plugin.h
/usr/include/gegl-0.0/gegl-buffer.h
/usr/include/gegl-0.0/gegl-paramspecs.h
/usr/include/gegl-0.0/gegl-color.h
/usr/include/gegl-0.0/gegl-path.h
/usr/include/gegl-0.0/gegl-curve.h