/usr/include/GNUstep/BioCocoa is in libbiococoa-dev 2.2.2-2+b1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/include/GNUstep/../../lib/GNUstep/Frameworks/BioCocoa.framework/Headers
/usr/include/GNUstep/../../lib/GNUstep/Frameworks/BioCocoa.framework/Headers