can't install net/poptop with KERNPPP=on
..
===>  Building for poptop-1.4.0
gmake[2]: Entering directory `/usr/ports/net/poptop/work/pptpd-1.4.0'
gmake  all-am
gmake[3]: Entering directory `/usr/ports/net/poptop/work/pptpd-1.4.0'
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c pqueue.c
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c pptpd.c
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c configfile.c
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c pptpmanager.c
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c compat.c
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c inststr.c
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c getopt.c
compat.c:123:21: warning: format string is not a string literal (potentially insecure) [-Wformat-security]                                          [45/1899]
       setproctitle(proctitle);
                    ^~~~~~~~~
compat.c:168:5: warning: implicit declaration of function 'strerror' is invalid in C99 [-Wimplicit-function-declaration]
    syslog_perror("sigpipe write");
    ^
./our_syslog.h:38:62: note: expanded from macro 'syslog_perror'
#define syslog_perror(s)        syslog(LOG_ERR, "%s: %s", s, strerror(errno))
                                                             ^
compat.c:168:5: warning: format specifies type 'char *' but the argument has type 'int' [-Wformat]
    syslog_perror("sigpipe write");
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./our_syslog.h:38:62: note: expanded from macro 'syslog_perror'
#define syslog_perror(s)        syslog(LOG_ERR, "%s: %s", s, strerror(errno))
                                                     ~~      ^~~~~~~~~~~~~~~
compat.c:178:3: warning: implicit declaration of function 'memset' is invalid in C99 [-Wimplicit-function-declaration]
  memset(&sa, 0, sizeof(sa));
  ^
compat.c:194:5: warning: format specifies type 'char *' but the argument has type 'int' [-Wformat]
    syslog_perror("sigpipe read");
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./our_syslog.h:38:62: note: expanded from macro 'syslog_perror'
#define syslog_perror(s)        syslog(LOG_ERR, "%s: %s", s, strerror(errno))
                                                     ~~      ^~~~~~~~~~~~~~~
5 warnings generated.
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c getopt1.c
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c pptpctrl.c
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c ctrlpacket.c
cc -DHAVE_CONFIG_H -I. -I.    -O2 -pipe -I/usr/ports/net/poptop/work/ppp-2.4.5 -fno-strict-aliasing -fno-builtin -DSBINDIR='"/usr/local/sbin"' -DETCDIR='"/us
r/local/etc"' -c pptpgre.c
pptpctrl.c:595:32: error: variable has incomplete type 'struct termios'
                struct termios tios;
                               ^
/usr/include/libutil.h:85:8: note: forward declaration of 'struct termios'
struct termios;
       ^
pptpctrl.c:600:21: warning: implicit declaration of function 'tcgetattr' is invalid in C99 [-Wimplicit-function-declaration]
                if (tcgetattr(tty_fd, &tios) < 0) {
                    ^
pptpctrl.c:605:35: error: use of undeclared identifier 'ECHO'
                tios.c_lflag &= ~(ECHO | ECHONL);
                                  ^
pptpctrl.c:605:42: error: use of undeclared identifier 'ECHONL'
                tios.c_lflag &= ~(ECHO | ECHONL);
                                         ^
pptpctrl.c:606:21: warning: implicit declaration of function 'tcsetattr' is invalid in C99 [-Wimplicit-function-declaration]
                if (tcsetattr(tty_fd, TCSAFLUSH, &tios) < 0) {
                    ^
pptpctrl.c:606:39: error: use of undeclared identifier 'TCSAFLUSH'
                if (tcsetattr(tty_fd, TCSAFLUSH, &tios) < 0) {
                                      ^
2 warnings and 4 errors generated.
gmake[3]: *** [pptpctrl.o] Error 1
gmake[3]: *** Waiting for unfinished jobs....
gmake[3]: Leaving directory `/usr/ports/net/poptop/work/pptpd-1.4.0'
gmake[2]: *** [all] Error 2
gmake[2]: Leaving directory `/usr/ports/net/poptop/work/pptpd-1.4.0'
===> Compilation failed unexpectedly.
Try to set MAKE_JOBS_UNSAFE=yes and rebuild before reporting the failure to
the maintainer.
*** Error code 1

Stop.
make[1]: stopped in /usr/ports/net/poptop
*** Error code 1

Stop.
make: stopped in /usr/ports/net/poptop

===>>> make failed for net/poptop
===>>> Aborting update

===>>> Killing background jobs
Terminated