MKuserdefs.sh is called with sh -x during ncurses build and when building world with -s output looks like this:
===> lib/ncurses/ncurses (obj,all,install) + AWK=awk + shift 1 + OPT1=1 + shift 1 + cat + cat + ./make_hash 1 user 1 + cat /usr/src/contrib/ncurses/include/Caps /usr/src/contrib/ncurses/include/Caps-ncurses + cat ===> lib/libpam/libpam (obj,all,install)