pkg/56936: posix_openpt(O_RDWR | O_NOCTTY) fails when configuring pkgsrc/x11/mlterm

[rokuyama.rk%gmail.com@localhost]

>Number:         56936
>Category:       pkg
>Synopsis:       posix_openpt(O_RDWR | O_NOCTTY) fails when configuring pkgsrc/x11/mlterm
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    pkg-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jul 22 11:20:00 +0000 2022
>Originator:     Rin Okuyama
>Release:        9.0, 9.2 (?)
>Organization:
Department of Physics, Meiji University
>Environment:
NetBSD nb9 9.2 NetBSD 9.2 (GENERIC) #0: Wed May 12 13:15:55 UTC 2021  mkrepro%mkrepro.NetBSD.org@localhost:/usr/src/sys/arch/amd64/compile/GENERIC amd64
>Description:
pkgsrc/x11/mlterm tries to detect whether system has working
posix_openpt(3) as:

mlterm-3.9.2/baselib/configure:
----
...
  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h.  */
#include <fcntl.h>
int
main ()
{
return posix_openpt(O_RDWR | O_NOCTTY) == -1;
  ;
  return 0;
}
_ACEOF
if ac_fn_c_try_run "$LINENO"; then :
...
----

This is expected to pass for NetBSD, but it does not for some cases.

For official package build of pkgsrc-2022Q[12] and -2021Q4 for amd64,
i386, and aarch64 (for 9.0), this test failed and configure fell back
to old BSD pty.

Also, there is report on netbsd-users@, in which x11/mlterm is
misconfigured for NetBSD/amd64 9.2:

https://mail-index.netbsd.org/netbsd-users/2022/07/21/msg028733.html

On the other hand, for pkgsrc-current for NetBSD/amd64 9.0:

http://ftp.netbsd.org/pub/pkgsrc/packages/NetBSD/amd64/.9.0-current-2022-07-15-22.09-being-update/All/mlterm-3.9.2nb3.tgz

this test succeeded, and mlterm uses posix_openpt(3) appropriately.

Also, I could not reproduce the problem by myself for freshly-installed
NetBSD/amd64 9.2:

- Manually compiled conftest.c above passes as expected.
- x11/mlterm from pkgsrc-2022Q2 is successfully configured to use
  posix_openpt(3).
>How-To-Repeat:
N/A
>Fix:
N/A