How can I add new binaries to the mfsroot image?

[Peter Steele]

I want to make a custom FreeBSD install CD-ROM with additional commands
available in the mfsroot image. Adding the new commands to the image is
easy enough, and I've made an install.cfg file on the CD-ROM as well so
that when the CD runs the commands in install.cfg are automatically
executed. This all works, except none of the new binaries I add to the
mfsroot image run during the automated sysinstall session. If I
reference one of the default commands (the ones stored in /stand) they
run fine, but if I add a new FreeBSD binary to the /stand directory
(e.g. gmirror), the command fails.

 

What's weird is that I can open a fixit shell after the install.cfg
script fails and then run the same commands interactively and they work
fine. Why would work these commands work in an interactive fixit shell
but not during the automated sysinstall session?