When using "su - myuser" to change from root to a non-privileged user,
"mesg n" from the default .profile fails with "mesg: error: tty device
is not owned by group `tty' or "mesg: cannot open /dev/ttyS0:
Permission denied", depending on whether mesg comes from busybox or
util-linux.
This does not happen during a normal login because permissions on
/dev/tty* get changed while doing that, something that isn't possible
with plain "su -".
As the error can't be avoided and failures of mesg probably aren't
particularly important, now error messages get dumped to /dev/null.
[YOCTO #11127]
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com> Signed-off-by: Ross Burton <ross.burton@intel.com>
