The "make install" tasks for fvwm (slight chance it's xpm -- I'm kind of hazey on that) assumes you have a path to X11R6/bin. That wasn't the case for root. Fix: I added X11R6/bin to the path for root, and then: make install Eventually worked. How-To-Repeat: as userid not root: Fetch and build ldconfig (bindist had wrong one) su to root, and make install. Fetch and build xpm su to root and make install. Fetch and build fvwm su to root make install make tries to run mkdirhier, which is in X11R6/bin. root doesn't have that in path -- fails to install.
State Changed From-To: open->closed mkdirhier is not used anymore -- /usr/X11R6/lib/X11/config/FreeBSD.cf has "MKDIRHIER = mkdir -p".