Seems I can't "unforget" erroneously forgotten files, so will have to forget them and then re-add them
# *** Change this file if and only if you are rebuilding from a new
# upstream baseline ***
# This package was branched from
# http://developer.symbian.org/oss/MCL/sftools/dev/build)
# at Mercurial revision:
0f5e3a7fb6af