Problem pointing /bin/sh to dash

[Jerome Warnier <jwarnier@beeznest.net>]

On Debian GNU/Linux (starting from Etch), I'm used to replace
the /bin/sh link to /bin/dash (points to /bin/bash by default).
It fails very badly (the system is almost unusable after reboot)
because /bin/mount is a shell script (from package freebsd-utils) using
"exec -a" (exec is a shell builtin), which seems to be a bashism.
So:
1) we find another way to do "exec -a" the POSIX-way (if at all
possible)
2) we change the shebang to #!/bin/bash instead of #!/bin/sh

Thanks
-- 
Jérôme Warnier
FLOSS Consultant
http://beeznest.net