anchor.diff:  { stdenv, appleDerivation, lib
  -, Librpcsvc, apple_sdk, pam, CF, openbsm }:
  +, libutil, Librpcsvc, apple_sdk, pam, CF, openbsm }:
   
   appleDerivation {
     # xcbuild fails with:
  
positive.code:   # see issue facebook/xcbuild#188
    # buildInputs = [ xcbuild ];
  
    buildInputs = [ Librpcsvc apple_sdk.frameworks.OpenDirectory pam CF
                    apple_sdk.frameworks.IOKit openbsm ];
    # NIX_CFLAGS_COMPILE = lib.optionalString hostPlatform.isi686 "-D__i386__"
    #                    + lib.optionalString hostPlatform.isx86_64 "-D__x86_64__"
  
negative.code:       --replace bsm/audit_session.h bsm/audit.h
      substituteInPlace login.tproj/login_audit.c \
        --replace bsm/audit_session.h bsm/audit.h
    '' + lib.optionalString stdenv.isAarch64 ''
      substituteInPlace sysctl.tproj/sysctl.c \
        --replace "GPROF_STATE" "0"
      substituteInPlace login.tproj/login.c \
        --replace "defined(__arm__)" "defined(__arm__) || defined(__arm64__)"
    '';
  
    buildPhase = ''
  