(setenv _ #f) fails

[mmc@maruska.dyndns.org (Michal Maruška)]

.. but the manual says: If val is #f, then any entry for var is deleted.

Welcome to scsh 0.6.1 (Combinatorial Algorithms)
Type ,? for help.

> (run (ls))
CVS                diff.scm.~4~          install.scm.~6~
bin                diff.scm.~5~          ldd-files.scm  
bin.~1~            find-broken-bins.scm  ldd-files.scm.~
bin.~2~            finddup.scm           modprobe.scm   
bin.~3~            finddup.scm.~1~       mount-remote.sc
build              finddup.scm.~2~       mount-remote.sc
configure.scm.~1~  hd.scm                mount.scm      
cron               hd.scm.~1~            mount.scm.~1~  
deposit.scm        hd.scm.~2~            mount.scm.~2~  
diff.scm           install.scm.~1~       mount.scm.~6~  
diff.scm.~1~       install.scm.~2~       mount.scm.~7~  
diff.scm.~2~       install.scm.~5~       mz.scm         
0
> (setenv "ZDOTDIR" #f)
> (run (ls))

Error: STRINGS parameter not list.
       #f
       #{Procedure 8724 (string-join in string-lib)}
1>