/usr/include/GNUstep/ is in libaddresses-dev 0.4.7-1ubuntu4.
This file is owned by root:root, with mode 0o755.
..
/usr/include/GNUstep/AddressBook
/usr/include/GNUstep/Addresses
/usr/include/GNUstep/Frameworks/
/usr/include/GNUstep/Frameworks/Addresses.framework/
/usr/include/GNUstep/Frameworks/Addresses.framework/Headers
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADAddressBook.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADConverter.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADEnvelopeAddressBook.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADGlobals.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADGroup.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADImageLoading.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADLocalAddressBook.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADMultiValue.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADPListConverter.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADPerson.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADPlugin.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADPublicAddressBook.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADRecord.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADSearchElement.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADTypedefs.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/ADVCFConverter.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/AddressBook.h
/usr/include/GNUstep/Frameworks/Addresses.framework/Versions/0/Addresses.h