When I try and do pkg help install or man 2 open on the serial console of a SandyBridge box, it doesn't seem to want to render the manpages with *roff. If I do it on the VGA redirected console over IPMI, it works. The processes appear to be stuck in ttydcd state. (please disregard the build date; the svn revision is the part of interest -- the last merge I did with my github fork was about 8 days ago) % uname -a FreeBSD mina3008.localdomain 11.0-CURRENT FreeBSD 11.0-CURRENT #0 a32b4d9(master): Thu Jul 17 02:58:38 PDT 2014 root@mina3008.localdomain:/usr/obj/scratch/freebsd/sys/GENERIC amd64 % pkg help install load: 0.00 cmd: more 1361 [ttydcd] 1.23r 0.00u 0.00s 0% 2636k load: 0.00 cmd: more 1361 [ttydcd] 1.47r 0.00u 0.00s 0% 2636k load: 0.00 cmd: more 1361 [ttydcd] 1.71r 0.00u 0.00s 0% 2636k load: 0.00 cmd: more 1361 [ttydcd] 1.91r 0.00u 0.00s 0% 2636k q^C% man 2 open load: 0.00 cmd: more 1374 [ttydcd] 1.47r 0.00u 0.00s 0% 2636k
I just tried to do sysctl kern.conftxt | less and I ran into the same issue, so it looks like output paging in general is broken on the serial console.
Happens with syscons too, so I guess vt isn't necessarily to blame.
Peter H pointed me in the right direction (I missed this section in UPDATING): 20140405: The uart(4) driver has been changed with respect to its handling of the low-level console. Previously the uart(4) driver prevented any process from changing the baudrate or the CLOCAL and HUPCL control flags. By removing the restrictions, operators can make changes to the serial console port without having to reboot. However, when getty(8) is started on the serial device that is associated with the low-level console, a misconfigured terminal line in /etc/ttys will now have a real impact. Before upgrading the kernel, make sure that /etc/ttys has the serial console device configured as 3wire without baudrate to preserve the previous behaviour. E.g: ttyu0 "/usr/libexec/getty 3wire" vt100 on secure