Really simple patch to allow building with the --with-vfs-afsacl option 
 
*** samba-3.0.20pre1/source/modules/vfs_afsacl.c        2005-02-25 
11:59:33.000000000 -0600 
--- samba-3.0.20pre1.blt/source/modules/vfs_afsacl.c    2005-06-30 
12:41:42.583406429 -0500 
*************** 
*** 31,41 **** 
 
  #define MAXSIZE 2048 
 
! extern DOM_SID global_sid_World; 
! extern DOM_SID global_sid_Builtin_Administrators; 
! extern DOM_SID global_sid_Builtin_Backup_Operators; 
! extern DOM_SID global_sid_Authenticated_Users; 
! extern DOM_SID global_sid_NULL; 
 
  static char space_replacement = '%'; 
 
--- 31,41 ---- 
 
  #define MAXSIZE 2048 
 
! extern const DOM_SID global_sid_World; 
! extern const DOM_SID global_sid_Builtin_Administrators; 
! extern const DOM_SID global_sid_Builtin_Backup_Operators; 
! extern const DOM_SID global_sid_Authenticated_Users; 
! extern const DOM_SID global_sid_NULL; 
 
  static char space_replacement = '%';