Problem with isc_named

Hi!

With current (OpenBSD 6.7-current (GENERIC.MP) #232: Sat May 30 18:17:19
MDT 2020) and up-to-date packages, I'm having a hard time running isc_named
as a slave dns.

I get this in the log:
dumping master file: tmp/tmp-lxMn2v1tJx: open: file not found

named.conf is like this:
options {
directory "/tmp"; // working directory, inside the /var/named
chroot
// - must be writable by _bind
version ""; // remove this to allow version queries

listen-on { any; };
listen-on-v6 { any; };

empty-zones-enable yes;

allow-recursion { clients; };
};

zone "0.168.192.in-addr.arpa" {
type slave;
masterfile-format text;
file "tmp/0.168.192.in-addr.arpa";
masters { 192.168.0.4; };
};

zone "antarctica.no" {
type slave;
masterfile-format text;
file "tmp/antarctica.no";
masters { 192.168.0.4; };
};

zone "carebears.no" {
type slave;
masterfile-format text;
file "tmp/carebears.no";
masters { 192.168.0.4; };
};


/var/named/tmp is owned by _bind:_bind with drwxrwxr-x

I can't seem to find any error in my config. Could there be something wrong
with the package?
isc-bind-9.16.3p0v0 is the one I have installed.