@verb #3797:"chan_opts" this none this rxdo #833
@program #3797:"chan_opts" this none this
$perm_utils:can_hack() || raise(E_PERM)
{id, @opts} = args
{members, history, atime, @oldopts} = `this:get_chan(id) ! E_INVARG => {{}, {}, 0}'
this:set_chan(id, {members, history, time(), @opts})
.