There are a couple of bugs in rev. 1.27:

There are a couple of bugs in rev. 1.27:
1) The man page should describe the code, not the other way around.
2) Internal variables should not be documented or exposed, except in
   controlled circumstances (i.e. - That's what the -C flag is for).
   The variable should have been saved to the config file in save_config().
3) The next available userid doesn't get automatically updated. The
   end-result is the same (user gets added with the correct uid),
   but in an interactive session the default uid doesn't get updated in
   the display.

So,

o Use the uidstart variable instead of uuid (bug #3)
o Actually save the variable to adduser.conf (bug #2)
o (bug #1 to be fixed in an upcomming commit to adduser.conf.5)

MFC After: 2 weeks