sig-signing-type breaks `named-checkconf -p` pretty output

Summary

When using the “sig-signing-type” keyword found inside a zone clause, it causes the named.conf file checker to silently exit with error code 1.

BIND version used

named v9.16.15

Steps to reproduce

The named.conf file simply has the following excerpt:

zone “public” {
   # . . .
   sig-signing-type 65243
   # . . .
};

Running

named-checkconf  -t .  -p  named.conf

will no longer output any content of the file.

What is the current bug behavior?

No longer outputs any file content

Exit code 1

What is the expected correct behavior?

Expected the original (but nicely rearranged) output of named.conf.

Relevant configuration files

Relevant logs and/or screenshots

No error output, no output output, just silent exit with an error code of 1.

Possible fixes

(If you can, link to the line of code that might be responsible for the problem.)