pkg/46957: screen doesn't work with ptyfs on NetBSD

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>Number:         46957
>Category:       pkg
>Synopsis:       screen doesn't work with ptyfs on NetBSD
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Sep 15 09:55:00 +0000 2012
>Originator:     Alan Barrett
>Release:        NetBSD 6.99.10
>Organization:
Not much
>Environment:
System: NetBSD 6.99.10 i386
Architecture: i386
Machine: i386
>Description:
        screen-4.0.3nb4 and screen-4.0.3nb5 are both unable to allocate
        PTY devices under NetBSD with ptyfs mounted on /dev/pts.  (The
        change in revision 1.11 of pkgsrc/misc/screen/patches/patch-aa
        did not help.)

>How-To-Repeat:
        Mount ptyfs, using this line in /etc/fstab:

                ptyfs /dev/pts ptyfs rw 0 0

        Install screen-4.0.3nb5 from pkgsrc/misc/screen.

        Attempt to run screen.

        See the error messages "No more PTYs." and "Sorry, could not
        find a PTY.".

        I tried turning off the setuid bit on /usr/pkg/bin/screen-4.0.3
        and then running it under ktrace.  The following lines appear to
        be relevant:

screen-4.0.3 CALL  open(0x8090fa0,0x8002,0xbbbf47a5)
screen-4.0.3 NAMI  "/dev/ptmx"
screen-4.0.3 RET   open 5
screen-4.0.3 CALL  
__sigaction_sigtramp(SIGCHLD,0xbfbfdba0,0xbfbfdbb8,0xbbaedc40,2)
screen-4.0.3 RET   __sigaction_sigtramp 0
screen-4.0.3 CALL  ioctl(5,TIOCPTSNAME,0xbbb83e80)
screen-4.0.3 RET   ioctl -1 errno 28 No space left on device
screen-4.0.3 CALL  
__sigaction_sigtramp(SIGCHLD,0xbfbfdba0,0xbfbfdbb8,0xbbaedc40,2)
screen-4.0.3 RET   __sigaction_sigtramp 0
screen-4.0.3 CALL  close(5)
screen-4.0.3 RET   close 0
screen-4.0.3 CALL  fcntl(3,4,0)
screen-4.0.3 RET   fcntl 0
screen-4.0.3 CALL  write(3,0xbb91b000,0x25)
screen-4.0.3 GIO   fd 3 wrote 37 bytes
        "\^[[H\^[[J\^[[24B\^[[7mNo more PTYs.\^[[27m  \b\b"
screen-4.0.3 RET   write 37/0x25

>Fix:
        Workaround: don't use ptyfs