/usr/ is in liballeggl4-dev 2:4.4.2-10.
This file is owned by root:root, with mode 0o755.
..
/usr/include/
/usr/include/alleggl.h
/usr/include/allegrogl/
/usr/include/allegrogl/GLext/
/usr/include/allegrogl/GLext/gl_ext_alias.h
/usr/include/allegrogl/GLext/gl_ext_api.h
/usr/include/allegrogl/GLext/gl_ext_defs.h
/usr/include/allegrogl/GLext/gl_ext_list.h
/usr/include/allegrogl/GLext/glx_ext_alias.h
/usr/include/allegrogl/GLext/glx_ext_api.h
/usr/include/allegrogl/GLext/glx_ext_defs.h
/usr/include/allegrogl/GLext/glx_ext_list.h
/usr/include/allegrogl/GLext/wgl_ext_alias.h
/usr/include/allegrogl/GLext/wgl_ext_api.h
/usr/include/allegrogl/GLext/wgl_ext_defs.h
/usr/include/allegrogl/GLext/wgl_ext_list.h
/usr/include/allegrogl/alleggl_config.h
/usr/include/allegrogl/gl_ext.h
/usr/include/allegrogl/gl_header_detect.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/allegrogl.pc
/usr/share/
/usr/share/doc/
/usr/share/doc/liballeggl4-dev/
/usr/share/doc/liballeggl4-dev/copyright
/usr/lib/x86_64-linux-gnu/liballeggl.so
/usr/share/doc/liballeggl4-dev/CHANGES.gz
/usr/share/doc/liballeggl4-dev/changelog.Debian.gz