port-sun3/57741: sshd fails to open a PTY on NetBSD/sun3

[thorpej%me.com@localhost]

>Number:         57741
>Category:       port-sun3
>Synopsis:       sshd fails to open a PTY on NetBSD/sun3
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    port-sun3-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Dec 01 20:45:00 +0000 2023
>Originator:     Jason Thorpe
>Release:        10.0_RC1
>Organization:
CISCy Business
>Environment:
NetBSD sun3-160 10.0_RC1 NetBSD 10.0_RC1 (GENERIC) #0: Wed Nov 29 12:36:24 UTC 2023  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/sun3/compile/GENERIC sun3

(Running in TME.)
>Description:
sshd fails to open a PTY:

Dec  1 12:34:59 sun3-160 sshd[793]: error: openpty: No such file or directory
Dec  1 12:35:00 sun3-160 sshd[814]: error: session_pty_req: session 0 alloc failed

sun3-160$ ls -l /dev/ptm*
crw-rw-rw-  1 root  wheel  165, 1 Dec  1 10:44 /dev/ptm
crw-rw-rw-  1 root  wheel  165, 0 Dec  1 10:44 /dev/ptmx
sun3-160$ 

Sure enough:

sun3-160$ cat /dev/ptmx 
cat: /dev/ptmx: No such file or directory
sun3-160$ 

the-ripe-vessel:thorpej 29$ cat /dev/ptmx
^C
the-ripe-vessel:thorpej 30$ 

>How-To-Repeat:
See above.
>Fix:
Not provided.