/usr/include/GNUstep/NGLdap/ is in libsope-dev 2.2.17-1build2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/GNUstep/NGLdap/EOQualifier+LDAP.h
/usr/include/GNUstep/NGLdap/NGLdap.h
/usr/include/GNUstep/NGLdap/NGLdapAttribute.h
/usr/include/GNUstep/NGLdap/NGLdapConnection.h
/usr/include/GNUstep/NGLdap/NGLdapDataSource.h
/usr/include/GNUstep/NGLdap/NGLdapEntry.h
/usr/include/GNUstep/NGLdap/NGLdapFileManager.h
/usr/include/GNUstep/NGLdap/NGLdapGlobalID.h
/usr/include/GNUstep/NGLdap/NGLdapModification.h
/usr/include/GNUstep/NGLdap/NGLdapSearchResultEnumerator.h
/usr/include/GNUstep/NGLdap/NGLdapURL.h
/usr/include/GNUstep/NGLdap/NSString+DN.h